The photodegradation of fungicide Fenarimol (FEN) by solar radiation, high pressure mercury lamp (HPML) and ultraviolet radiation (UV) has been studied on glass surface, in water or in organic solution, the effects of four kinds of surfactants and several kinds of pesticides has also been investigated. Some other factors, such as temperature,the water types, pH buffer solution, coloring matter, halogen ions, nitrate/nitrite, metallic ions, hydrogen peroxide and surfactants, their effects on photodegradatio...