The response of N 2 number density in thermosohere during two geomagnetic disturbance on March and October 2012 is analysed in this paper, data taken by Atmospheric Environment Detector on board Tiangong-1 spacecraft are used. Discuss the abnormal increase range, time and space characteristics, low latitude distribution and features of summer and winter hemisphere of N 2 number density during the geomagnetic storms. These results are as follows: the abnormal increase of N 2 number density is closely related to geomagnetic disturbance and its intensity, abnormal increase phenomenon usually appears in the high latitudes region of summer hemisphere, N 2 number density increase during the geomagnetic disturbance is closely related to the mechanism of atmospheric heat.