Accompanying increasing competition among the communication industry, maintaining and improving the stability and loyalty of customers has become the key determinant of profitability. In order to prevent the loss of customers, we need to identify the stable users by data mining model. Through the evaluation of three models, Random Forest model performs with better robustness. This model can describe and predict most of the stable users in a shorter period of time. Consequently, the result will provide operators with the advantage of adopting reasonable marketing tactics timely.