Water quality in water distribution system is changed biological, physicochemical and organoleptic qualities, and then it has been more worse. Chlorine residual was used to as indicator for prediction of water quality behavior, characteristics and ensurement of regulatory requirment. Therefore, M&O of chlorine residual is to be important for water quality management in water distribution system. This study was performed to study the relationship for water quality changes and characteristic of chlorine residual decay according to pipe type and diameter, hydraulic effect, and water quality parameter. Results of this study indicated decay coefficient of chlorine residual was to characterized with pipe type and diameter. Also it was to different hydraulic effect and initial chlorine residual concentration and water quality parameter as temperature, TOC, etc.