The localization of mobile robot is an important part of control problem. Pseudolite Ultrasonic System (PUS) is the method to find an absolute position by using ultrasonic sensor. PUS can be able to estimate the position of mobile robot precisely, in which errors are not accumulated. PUS insure a high accuracy on static state. But mobile robot moves as fast as an estimated position errors are increased. In this paper, we propose a compensation method to increase the accuracy of estimated position on moving robot by using PUS and Gyro. PUS take a 400 milliseconds to estimate mobile robot's position one time. This method can calculate a position on increased sampling period, 100 milliseconds at once. Also a Kalman filter is employed for PUS and Gyro integration. This integrated system provides more accuracy of mobile robot position. The performance of PUS and Gyro integrated system showed its effectiveness from the result of the simulation and the experiment.