Overhead crane is used widely to convey the pay-load due to its convenience. It is difficult to convey the payload without payload sway for operators. Payload sway causes not only decreasing safety but also decreasing convey efficiency. Therefore it is demanded both conveying trolley to target position and suppressing payload sway. But it is difficult to achieve both conveying trolley to target position and suppressing payload sway. In this paper, assist control by emulating natural damping method is proposed. Natural damping is defined as energy damping of crane system caused by trolley friction. Not only trolley but also payload energy is damped by natural damping. Natural damping can achieve both trolley position convergence and payload sway suppression.