The current study，using a sample of 1915 Beijing residents，investigated the characteristics of the mobile phone addiction and its related factors. The results showed the following：（1）the mobile phone addiction of Beijing residents has a medium level；（2）the levels of dimensions of the mobile phone addiction，from low to high，were social comfort，App update，withdrawal behavior，negative influence，prominent behavior，and App use；（3）there were gender，age，educational level，and subjective socioeconomic status differences in the mobile phone addiction of Beijing residents；（4）the mobile phone addiction was significant and positive correlated with both depression and anxiety，while it negatively correlated with self-esteem，social support，and mental health.