The purpose of this study was to discuss the interactions of risk evaluation between the senior citizens and non-senior groups for being membership of indoor warm water swimming pool club. Factor analysis, t-test and Two-way MANOVA were utilized for data analysis. The results indicated that the senior groups were significantly superior to the non-senior groups in "physical risk" and "functional risk"; male performed better in "psychological risk", "physical risk" and "functional risk" over female; non-members were extremely superior to members in "social risk", "psychological risk" and "physical risk". There is significant interaction between age groups and occupation regarding with the risk evaluation. Among respondents who were freelanced, non-senior groups were significantly superior to the senior groups in "psychological risk". Among the senior respondents, people working in business industry were significantly better than people in agriculture industry and free lanced in "psychological risk". It is suggested that the management of indoor warm water swimming pool clubs hire certified lifeguard and have them trained constantly. It is necessary to maintain hygiene of the environment, such as sauna room. steam room and change room, etc. It is also important to have clean water and present water test statistics to the public. On the other hand, the swimming pool club can think of more flexible payment methods, for example, combined with MRT card or refill card issuance in order to attract more people joining the membership.