With the recent development of commercial sports clubs, the behavioral characteristics of members are receiving increased attention from sports management researchers. The purpose of this study is to identify the behavioral characteristics of Japanese commercial sports club members. The 416 samples were selected at two commercial sports clubs in Tokyo. The sample was categorized into four groups using a two-dimensional analyzing model, the two dimensions being frequency of participation in activities and the way members commitment their sports club in their minds. These four groups have the following respective characteristics: both frequency and commitment of the club are high (Group 1) , frequency is high but commitment of the club is low (Group 2) , both frequency and commitment of the club are low (Group 3), and frequency is low but commitment of the club is high (Group 4). ANOVA has revealed that member's evaluation of club service and mobility between clubs are useful for classifying club members into the four categories. Members belonging to [Group 1] are satisfied with the assurance and empathy of club service, while members belonging to [Group 4] are satisfied with the service's tangibility, reliability and responsiveness. Members in [Group 2] think of moving to another club when the club gets too crowded, while members belonging to [Group 3] think of moving to another club when the member's fee rises and accessibility becomes difficult.