This paper studies the contract design problem between a polluter and an environmental company (called "EC" hereafter) providing pollution abatement service. The risk preference of both sides are considered and the payment from the polluter to the EC is assumed to be composed of two parts: A fixed payment and a linear variable payment depending on the realized abatement. The optimal fixed/variable payments are discussed in three scenarios: Under complete information, a single contract under information asymmetry, a menu of contracts under information asymmetry. The results show that:1)When the information is complete, the expected revenue of the EC is equal to the sum of pollution abatement cost and risk cost. 2)When the information is incomplete, the polluter can always benefit from providing a menu of alternative contracts rather than a single contract. 3) The effect of abatement cost and environmental uncertainty on the optimal variable payment depends on the risk preference of two sides. 4)The polluter gets maximal/minimal expected utility when both sides are risk neutral/averse.