Evidence from various research areas such as cross-cultural psychology indicated that there are significant geographical patterns of human psychological and behavioral characteristics. On the other hand，media analysis theorists suggested that the use of electronic media will break the geographical constraints on the dissemination of information. Then whether there are geographical clustering patterns of people’s online information use behavior and social mentality characteristics？It’s an important topic to be tested. With the objective behavioral data of Weibo and WeChat users from 100 Chinese cities，this paper systematically analyzed and summarized the information behavior characteristics of urban netizens from the aspects of netizens’ attention，emotion，and motivations. Results indicated that Chinese urban netizens show great regional differences in the social mentality of netizens，and they also have different characteristics in the two main information fields，namely Weibo and WeChat. Therefore，we proposed the concepts of “online city clusters” and “online city cards” according to the city’s similarity in the use behavior of information. It is of great reference value to deeply characterize the social mentality of urban Chinese netizens，and to explore the social mentality adjustment strategies and guiding mechanism of urban netizens according to local conditions.