Abstract: After studied smartphone’s sensors and indoor magnetic field, an indoor localization system based on Client／Server architecture is designed. With the three axis fluxgate geomagnetic sensor, we can collect geomagnetic signals and establish fingerprint in two different ways: coordinate transformation of the three axis geomagnetic data with the assist of the data of gyroscope; combination of geomagnetic data and azimuth information. Then, generate the grid map as the indoor positioning reference map, and design geomagnetic matching algorithm based on euclidean distance. Finally, the application is deployed on the Android platform and experiments are conducted, then compare accuracy and matching speed in different location fingerprint. The experimental results show that the system can achieve a positioning accuracy of 1m.