diff --git a/api/@ohos.i18n.d.ts b/api/@ohos.i18n.d.ts
index 79c4ac7738123dc0693d23febcfbed1b563543eb..339f5d0c52e37911d4140ecc78b995fed527a16d 100644
--- a/api/@ohos.i18n.d.ts
+++ b/api/@ohos.i18n.d.ts
@@ -330,4 +330,125 @@ export class Calendar {
  * @since 8
  */
 export function isRTL(locale: string): boolean;
+
+/**
+ * Sequence text can be grouped under the specified area,
+ * and grouping index with different lengths can be specified.
+ * @sysCap null
+ * @since 8
+ */
+export class IndexUtil {
+    /**
+     * Get IndexUtil object.
+     * @sysCap null
+     * @param locale Indicates a character string containing the locale information, including
+     *               the language and optionally the script and region, for the NumberFormat object.
+     * @return Returns IndexUtil object.
+     * @since 8
+     */
+    getInstance(locale?:string): IndexUtil;
+
+    /**
+     * Get a list of labels for use as a UI index
+     * @sysCap null
+     * @return Returns a list of labels
+     * @since 8
+     */
+    getIndexList(): Array<string>;
+
+    /**
+     * Add the index characters from a Locale to the index.
+     * @sysCap null
+     * @param locale The locale whose index characters are to be added.
+     * @since 8
+     */
+    addLocale(locale: string);
+
+    /**
+     * Get corresponding index of the input text.
+     * @sysCap null
+     * @param text input text
+     * @since 8
+     */
+    getIndex(text: string): string;
+}
+
+/**
+ * Provides the API for accessing unicode character properties, sunch as whether a character is a digit.
+ * @sysCap null
+ * @since 8
+ */
+export class Character {
+    /**
+     * Determines whether the specified code point is a digit character
+     * @sysCap null
+     * @param char the character to be tested
+     * @return Returns true if the character is a digit character
+     */
+    isDigit(char: string): boolean;
+
+    /**
+     * Determines if the specified character is a space character or not.
+     * @sysCap null
+     * @param char the character to be tested
+     * @return Returns true if the character is a space character
+     */
+    isSpaceChar(char: string): boolean;
+
+    /**
+     * Determines if the specified character is a whitespace character
+     * @sysCap null
+     * @param char the character to be tested
+     * @return Returns true if the character is a whitespace character
+     */
+    isWhitespace(char: string): boolean;
+
+    /**
+     * Determines if the specified character is a RTL character or not.
+     * @sysCap null
+     * @param char the character to be tested
+     * @return Returns true if the character is a RTL character
+     */
+    isRTL(char: string): boolean;
+
+    /**
+     * Determines if the specified character is a Ideographic character or not.
+     * @sysCap null
+     * @param char the character to be tested
+     * @return Returns true if the character is a Ideographic character
+     */
+    isIdeograph(char: string): boolean;
+
+    /**
+     * Determines if the specified character is a Letter or not.
+     * @sysCap null
+     * @param char the character to be tested
+     * @return Returns true if the character is a Letter
+     */
+    isLetter(char: string): boolean;
+
+    /**
+     * Determines if the specified character is a LowerCase character or not.
+     * @sysCap null
+     * @param char the character to be tested
+     * @return Returns true if the character is a LowerCase character
+     */
+    isLowerCase(char: string): boolean;
+
+    /**
+     * Determines if the specified character is a UpperCase character or not.
+     * @sysCap null
+     * @param char the character to be tested
+     * @return Returns true if the character is a UpperCase character
+     */
+    isUpperCase(char: string): boolean;
+
+    /**
+     * Get the general category value of the specified character.
+     * @sysCap null
+     * @param char the character to be tested
+     * @return Returns the general category of the specified character.
+     */
+    getType(char: string): string;
+}
 }
\ No newline at end of file
diff --git a/api/@ohos.intl.d.ts b/api/@ohos.intl.d.ts
index 58f7d28ece511e19785cf640f65997c73872353e..1f53ea0e4b31a154a76a003c8ca67f21be604f89 100755
--- a/api/@ohos.intl.d.ts
+++ b/api/@ohos.intl.d.ts
@@ -581,5 +581,116 @@ export class PluralRules {
      */
     select(n: number): string;
 }
+
+/**
+ * Provides the input options of RelativeTimeFormat.
+ * @sysCap null
+ * @since 8
+ */
+ export interface RelativeTimeFormatInputOptions {
+    /**
+     * The locale matching algorithm to use.
+     * Possible values are: lookup, best fit
+     */
+    localeMatcher: string;
+
+    /**
+     * The format of output message.
+     * Possible values are: always, auto
+     */
+    numeric: string;
+
+    /**
+     * The length of the internationalized message.
+     * Possible values are: long, short, narrow
+     */
+    style: string;
+}
+
+/**
+ * Provides the resolved options of RelativeTimeFormat.
+ * @sysCap null
+ * @since 8
+ */
+export interface RelativeTimeFormatResolvedOptions {
+    /**
+     * The BCP 47 language tag for the locale actually used.
+     */
+    locale: string;
+
+    /**
+     * The length of the internationalized message.
+     * Possible values are: long, short, narrow
+     */
+    style: string;
+
+    /**
+     * The format of output message.
+     * Possible values are: always, auto
+     */
+    numeric: string;
+
+    /**
+     * The value requested using the Unicode extension key "nu" or filled in as a default.
+     */
+    numberingSystem: string;
+}
+
+/**
+ * Given a Time period length value and a unit, RelativeTimeFormat object enables
+ * language-sensitive relative time formatting.
+ * @sysCap null
+ * @since 8
+ */
+export class RelativeTimeFormat {
+    /**
+     * A constructor used to create RelativeTimeFormat object.
+     * @sysCap null
+     * @since 8
+     */
+    constructor();
+
+    /**
+     * A constructor used to create RelativeTimeFormat object.
+     * @sysCap null
+     * @param locale Indicates a character string containing the locale information, including
+     *               the language and optionally the script and region, for the RelativeTimeFormat object.
+     * @param options Indicates the options used to initialize RelativeTimeFormat object.
+     * @since 8
+     */
+    constructor(locale: string | Array<string>, options?: RelativeTimeFormatInputOptions);
+
+    /**
+     * formats a value and unit according to the locale and formatting options of this object.
+     * @sysCap null
+     * @param value Numeric value to use in the internationalized relative time message.
+     * @param unit Unit to use in the relative time internationalized message.
+     *             Possible values are: year, quarter, month, week, day, hour, minute, second.
+     * @returns formatted language-sensitive relative time.
+     * @since 8
+     */
+    format(value: number, unit: string): string;
+
+    /**
+     * returns an Array of objects representing the relative time format in parts that can be used for
+     * custom locale-aware formatting
+     * @sysCap null
+     * @param value Numeric value to use in the internationalized relative time message.
+     * @param unit to use in the relative time internationalized message.
+     *             Possible values are: year, quarter, month, week, day, hour, minute, second.
+     * @returns an Array of objects representing the relative time format in parts
+     * @since 8
+     */
+    formatToParts(value: number, unit: string): Array<object>;
+
+    /**
+     * Returns a new object with properties reflecting the locale and formatting options computed during
+     * initialization of the object.
+     * @sysCap null
+     * @returns RelativeTimeFormatOptions which reflecting the locale and formatting options of the object.
+     * @since 8
+     */
+    resolvedOptions(): RelativeTimeFormatResolvedOptions;
+}
 }
 export default intl;
\ No newline at end of file