[Objective] The aim was to seek for the photochemical degradation approach of controlling tetramethrin pollution in water.[Method] The influences of 3 light sources,2 humic acid concentrations,3 pigments and 3 surfactants on the photochemical degradation of tetramethrin pesticides in water were studied.[Result] The influences of different light sources on the photodegradation of tetramethrin in water had bigger difference,tetramethrin degraded fastest under high pressure mercury lamp,secondarily under ultra...