Many studies are carried on localization algorithm based on RSSI technology in WSNs

but the low-cost and easy-inplemented localization technology are vulnerable to environmental factors

so there would be a large error in distance estimation during ranging.According to the system state equation and measurement equation of dynamic system

system noise and measurement noise are added to the RSSI localization system and Kalman filtering algorithm is used to filter RSSI and to estimate the trajectory of mobile node.Simulation results show that the localization precision of trajectory of the mobile node is increased by the improved Kalman fitlering algorithm.