Hot spring Bathing is a popular activity in Taiwan, and encouraged by extended weekend policy. In order to provide high quality of hot springs for people and realize the possible effects on human and environment, we investigated the water quality of hot springs in Peito, Taipei.Forty water samples were collected from three sources, including Diregu, Danhuangtzuei, and Shuangchungshi hot spring areas in Peitou district. The physical, chemical and heavy metal concentrations of hot spring bath water collected in summer and winter were analyzed. The antimicrobial effects to E. coli, B. subtilis, and S. aureus of green sulfur spring and white sulfur spring were also examined.