Abstract: The April 2nd, 2012, M_L1.9 Xuhui earthquake of Shanghai occurred. Many buildings of Xuhui, Minhang and Pudong were shaken and hundreds of thousands of people in Shanghai felt this earthquake. We analyzed the felt earthquake of Shanghai, and then the basis of this. We elaborated the reason of this felt earthquake from the following several aspects: earthquake location, earthquake depth and intensity, origin time and population density and social influence. At last, we point out that the occurrence of earthquake is random because the earthquakes can not be accurately predicted. Therefore, it is particularly important to raise the public’s awareness of earthquake preparedness and disaster reduction.