Testing methods of Japanese Water Supply Act were revised in April 2013, and 64 pesticides were added to the target compounds of the simultaneous analytical method using LC/MS/MS. In this note, an InertSustain C18 HPLC column and a 4000QTRAP linear tandem mass spectrometer (AB Sciex) were used. As a result, all the compounds added by the revision were detected with excellent peak shape.