Abstract: This paper presented a novel self-adapting localization algorithm in wireless sensor networks based on optimized RSSI and MDS-MAP.The proposed algorithm uses two way to enhance the precision of localization:(1) an effective method to reduce the error of RSSI-measured distance had been designed;(2) the Small-World-Network theory had been employed to guide the selection of beacon nodes from normal nodes in WSN.On the base of aforementioned steps,we use MDS-MAP algorithm to carry out the localization tasks.Simulation experiments show that sound improvement on accuracy,self-adaptive,and stability has been achieved.