Experimental researches are made on the application of two extraction solvents S- 316( a polymer of chlorot rif luoroethylene) and CCl4 to the non-dispersive infrared analysis. By the comparison of the linearity, the measuring accuracy and the delect ion-limit,it shows that if the conditions of the operation and the purity of the ex traction solvent are cont rolled strictly,the result s must be the same: in the area of 2～200 mg/ L demarcated by the instrument it is linear; the measuring accuracy is about 1%, the detection limit is 0.1 mg/ L, and the recovery rate is over 85% .The demand in pract ice will be met entirely. But by the use of ext raction solvent CCl4, the cost is much less than that of extraction solvent S - 316. This method has a great value in the determination of oil-bearing amount in water, having wide use prospects in the environmental monitoring.