Context： This data set contains the communication of students with the smartphones in the schools in a week. We set a evaluation to describe the quality of the user the through the first 3 pieces of information. Content： Useful information : it means the pieces of useful information between communication. Connection frequency: it means the times the user connects to other users. Effective connection: it means the successful times of communication with others. Evaluation: it is set to judge the popularity of the users. Acknowledgements： It's collected by an online survey in several schools. Inspiration： Can we use the data to find popular student in the school? It's useful for teachers to choose students that good at making friends.