Abstract: Aiming at the inherent disadvantage of inertial navigation system (INS)that the positioning error are accumulated over time, the method of compensating errors in INS /dead reckoning(DR) integrated system was put forward. The main factors which begot errors in dead reckoning were analyzed, and the positioning error equation was given,then the Kalman filter was built for errors compensation of integrated system. The difference of velocity between INS and DR was used as the input of Kalman filter, the attitude error, velocity error, positioning error and the scale factor error of odometer were to be estimated which compensated the errors of integrated navigation system by feedback closed loop rectification. Two non-closed paths were selected in verification experiments.The positioning error of the first path is 3.49 and 2.3 before and after compensation respectively. And that of the second path is 2.4 and 2 before and after compensation respectively. Experiment results indicate that the system position accuracy is improved effectively by dead reckoning compensation method.