HELP! Mac Air, Wifi, Connecting Problem

My MBA suddenly have some problem connecting my WiFi at home, while my PC and Cellphone all doing fine. The problem is whenever I tried to connect internet with Air, Something like:"Another device on the network is uding your computer's IP address,try connecting again later. If you continue to have problems, change the IP address of this computer or the IP address of the other device. Contact the network administratot if you need more information." will pop out.

But actually, I did not have the mentioned "other devices" using the same IP.

Please help!