The number of viable microorganism in drinking water was monitored according to storage temperature and storage period. The number of general bacteria in underground water was 10²-10^5CFU/ml and that of coliform group was decreased after 7days. The number of general bacteria in bottle water was increased until 7days but decreased after that day. Coliform group in bottle water were detected only 1 sample. The number of general bacteria in purified water was 10³-10⁴CFU/ml and 10²-10⁴CFU/ml at 8 and 25, respectively. Coliform group were not detected in purified water.