Electron density profile data are collected in 2009 based on COSMIC occultation observation, and its statistical averages are calculated in each cell. Utilizing spherical harmonic function and calculating model values, we analyze the geomagnetic season variations of the maximum electron density and its distribution variations in the daytime and nighttime at mid and low latitude. We also discuss changes of electron density during geomagnetic activity. Research shows that the value of maximum electron density in the daytime was significantly higher than that of maximum electron density in the nighttime. Increase is particularly evident in the mid-latitude part of the region. The enhanced anomalous electron density disturbances took place from 150km to 550km altitude at mid and low latitude during geomagnetic activity. The values change with the latitude and increases with height.