INS/GPS integrated system has been one of the most popular methodologies in the research field of navigation technology. This paper aims at developing a real-time low-cost INS/GPS integrated navigator based on PC platform and reviewing many problems encountered in the development of real time system. A MEMS IMU is applied in the system to meet the requirements of low cost and small size. The proposed system utilizes Auto ZUPT/ZIHR as an accurate update source for EKF to improve the accuracy of navigation solutions during GPS signal blockages. In the end, various field tests which include a pure INS aided by ZUPT/ZIHR and NHC, a simple INS/GPS and an INS/GPS aided by ZUPT/ZIHR and NHC are conducted in downtown. The preliminary results illustrates the proposed system with frequent ZUPT/ZIHR provides a stable performance operating kinematically in free inertial mode without the aiding of GPS by 15 minutes with a low-cost IMU and the INS/GPS integrated solutions are improved by 50% when automatic ZUPT/ZIHR and NHC are applied in GPS denied areas.