Senior centers in apartment complex have been provided since 1980 according to the Housing Act in Korea. Nowadays these senior centers are model leisure facility for the elderly. However there are no specific guidelines for space composition and usage in a senior center. This study examines the space composition and usage patterns of 16 senior centers in apartment complex, Jangyou New Town. The data were collected by means of an observation, measuring, and interviews. The results are ; 1) A senior center consisted of one living room and two rooms for men and women would be appropriate; A living room is for common activities and two rooms for casual resting of each gender. 2) A kitchen is mainly used for setting the table or making tea. Thus, the living-dining-kitchen type would be appropriate. 3) Many rest rooms are located outside of a senior center and unisex one. The restroom should be separated by gender and located within the senior center. Also, the width of all doors should be more than 80cm and the floor be flat. The grab bars should be installed near the fixtures in a restroom. 4) Design and location of the shoe shelf are not convenient for the elderly to use. It should be designed and arranged for the elderly to use conveniently. Also, space for canes, walkers or wheelchairs should be considered in entrance area.