Because of excessive use of chemical fertilizer at Khuzestan province farms, each year volume equivalent 2 milliard meter cube drainage water import directly to Karun. With attention to high volume of agriculture’s pollution, determination factors affecting on farmers attitude to improve system planning in order to reduce water pollution have special importance. In recent study, in order to estimate wheat grower's tendency to payment in Province Molasanifor reduction of pollution in Karun river, contingent valuation method inclusive two method, Logit and two-step Heckman are used. The needed data collected with use of questionnaire and verbal interview with120 person and stochastic sampling method. Study result show that in both two Logic and Heckman models variable involve age, proposed price, river pollution reason, family size have negative effects on agricultures willing to pay. Also results show that each family willing to pay amount1880000 and 1640000 Rails in year for water pollution reduction. Reception farmers for assigned partial of own income in order to reduce Karun river pollution suggest of importance and position of this river between region`s farmers. At this meantime, to factors affecting amount of farmer’s payment in order to reinforcement farmers role to reduce river pollution have especial importance.