A method of power saving in a wireless local area network is provided. The method is performed by a wireless device that acquires TXOP (transmission opportunity) from an access point (AP), and the TXOP indicates an interval of time when the AP has the right to transmit at least one data block for multi user-multiple input multiple output (MU-MIMO) transmission. The method includes receiving a power saving indicator from the AP, the power saving indicator indicating whether the AP is allowed to enter doze state during the TXOP; and entering the wireless device into the doze state until the end of the TXOP if the power saving indicator indicates an allowance of entering the doze state.