The study of the inventory of pesticides qualitatively and quantitatively and the quality monitoring of subterranean waters of BEN SLIMANE's province by the analysis of some physico-chemical parameters make us to release some interactions between agricultural pesticides and environment. Inquiries realized in the zone of study, allowed the inventory of 63 pesticides agricultural use marketed, among which 21 Insecticides, 9 Weed-killers and 33 Fungicides with a total of 57 active Materials. The use of pesticides with agricultural use in the zone of study and the comparison of their degree of toxicity with the international standards, allowed us to raise certain risks bound to these substances, particularly the phytosanitary products the active materials of which belong to the classes Ib and II which represent a potential risk on the various components of the ecosystem and which require a follow-up in the future in the various components to know METHOMYL, DELTAMETHRINE, CYPERMETHRIN, THIACLOPRID, IMIDACLOPRID, TAU-FLUVALINATE, DIMETHOATE, BIFENTHRINE, 2,4-D. The physico-chemical quality subterranean waters of the zone of study respects the Moroccan standard, except the conductivity in 4 municipality OULAD LOUTA, MELLILA, FDALATE and SIDI BETACHE who and exceeded the standard because of the effect of the geologic nature on the quality of waters.