Through the development of smartphones and the development of communication technology,mobile communication has become an essential part of modern society.It is difficult to say about life without We Chat（Mobile Instant Message）in China.Already,there were over 1 billion We Chat users worldwide in 2019,and as of 2017,87.7% of users said they use it for business communication.As the organizational use of We Chat（MIM）increases rapidly,the need for research on the advantages and disadvantages of We Chat（MIM）is rising.Besides,in the modern business environment,variables such as rapid change and risk are making it more difficult for companies to survive.Many companies are trying to solve the given problems to survive in their environment.Companies that were struggling to solve problems have focused on team effectiveness as well as individuality.Therefore,to solve a given problem,a modern organization operates a team system.In this study,the researcher wants to investigate how team communication using We Chat affects individuals and teams.Furthermore,everything has both positive and negative sides,like both sides of a coin.In addition to maximizing the advantages,minimizing the disadvantages also leads to the best results.Therefore,this study chose Job Satisfaction,Job Stress,and Work-life Balance for the individual.For the team,Team Performance indicates the Team Effectiveness in terms of Problem-Solving because lots of researchers argued that Team Performance showed by Team Effectiveness.Shortly,this study aims to investigate how using We Chat for team communication affects Team Performance（Problem-Solving）.This study attempted to supplement the limitations of each method by conducting surveys and interviews—all participants in the polls and interviews conducted for people using We Chat for team communication.The number of participants in the study was 272,and the survey results were analyzed using SPSS 23.0.The interview was conducted with structured questions,and four interviewees have more than three years of work experience.First,as a result of research through a questionnaire,it was found that the use of We Chat for team communication has a positive effect on Job Satisfaction and Team Performance（Problem-Solving）.However,it did not appear to have a direct impact on Job Stress and Work-Life Balance.The usage-based weekly and the daily usage are not affected by the result.The result confirms that Job Satisfaction entirely mediated with We Chat use and Team Performance（Problem-Solving）,and Job Satisfaction was found to change Job Stress and Work-Life Balance.Moreover,Job Stress and WorkLife Balance are not directly affected by We Chat use but have a negative and positive effect on Team Performance（Problem-Solving）,respectively.As a result of the interview,team communication through We Chat has a positive impact on Job Satisfaction.Unlike the survey results,most respondents indicated that using We Chat for team communication can increase Job Stress.Also,some commented that it reduces Job Stress.Three-quarters of respondents said that using We Chat for team communication harmed WorkLife Balance,and the rest replied that there was no impact because the responder did not use We Chat outside of business hours.All respondents said that team communication through We Chat,Job Satisfaction,and Work-Life Balance had a positive effect on Team Performance（Problem-Solving）.However,different responses were given to the impact of Job Stress on Team Performance（Problem-Solving）.Summarizing the interview results,the effect of team communication through We Chat on Job Stress and Work-Life Balance was different from the survey results,and the rest was the same.Through the results of this study confirms the effect of team communication through We Chat（MIM）on Team Performance,which has an academic impact.Not only that,but it also has a practical effect.For example,it can provide guidelines for companies’ strategic communication.However,there are suggestions for follow-up studies.First,only Weekly usage affected variables such as Job Satisfaction,Job Stress,Work-Life Balance,and Team Performance（Problem-Solving）.A more in-depth study of daily consumption is needed.Second,it is necessary to investigate the areas where the results of the survey and interview are different.For instance,the usage of We Chat affects Job Stress and Work-Life Balance.Finally,this study conducted to identify correlations.Therefore,future studies can strengthen by considering demographic variables.