diff --git a/multimedia/player_framework/avplayer.h b/multimedia/player_framework/avplayer.h
index 1261bdd3b10c18efbed98887ede2416eefb081f2..29741964597102ab6754f3419c9730baec41501b 100644
--- a/multimedia/player_framework/avplayer.h
+++ b/multimedia/player_framework/avplayer.h
@@ -621,6 +621,29 @@ OH_AVErrCode OH_AVPlayer_SetOnErrorCallback(OH_AVPlayer *player, OH_AVPlayerOnEr
  */
 OH_AVErrCode OH_AVPlayer_SetVolumeMode(OH_AVPlayer *player, OH_AudioStream_VolumeMode volumeMode);
 
+/**
+ * @brief Sets the loudness gain of current media. The default gain is 0.0 dB. 
+ * This API can be called only when the AVPlayer is in the prepared, playing, paused completed or stopped state.	 
+ * The default loudness gain is 0.0dB. The stream usage of the player must be
+ * {@link OH_AudioStream_Usage#AUDIOSTREAM_USAGE_MUSIC}, {@link OH_AudioStream_Usage#AUDIOSTREAM_USAGE_MOVIE}
+ * or {@link OH_AudioStream_Usage#AUDIOSTREAM_USAGE_AUDIOBOOK}.
+ * The latency mode of the audio renderer must be {@link OH_AudioStream_LatencyMode#AUDIOSTREAM_LATENCY_MODE_NORMAL}.
+ * If AudioRenderer is played through the high-resolution pipe, this operation is not supported.
+ *
+ * @param player Pointer to an <b>OH_AVPlayer</b> instance.
+ * @param loudnessGain Loudness gain to set which changes from -90.0 to 24.0, expressing in dB.
+ * @return Function result code:
+ *         {@link AV_ERR_OK} If the execution is successful.
+ *         {@link AV_ERR_INVALID_VAL}:The value of <b>player</b> is a null pointer or
+ *                                    the value of <b>loudnessGain</b> is invalid.
+ *         {@link AV_ERR_INVALID_STATE}: The function is called in an incorrect state. or the stream usage of 
+ * 										audioRendererInfo is not one of {@link StreamUsage#STREAM_USAGE_MUSIC},
+ *                                 {@link StreamUsage#STREAM_USAGE_MOVIE} or {@link StreamUsage#STREAM_USAGE_AUDIOBOOK}.
+ *         {@link AV_ERR_SERVICE_DIED}:  System errors such as media service breakdown.                            
+ * @since 21
+ */
+OH_AVErrCode OH_AVPlayer_SetLoudnessGain(OH_AVPlayer *player, float loudnessGain);
+
 #ifdef __cplusplus
 }
 #endif