Abstract: Based on the single factor experiments, the response surface optimization experiments was used to research the extraction of phosphatidylinositol ( PI) with a quite high purity in solvent fractionation, using the soybean powder phospholipids from which the PC had been separated as raw material, and the purity of PI as the index.The best technological conditions of using alkaline ethanol as extracted solvent to extract phosphatidylinositol from soybean powder phospholipids were as follows: temperature 40℃, liquid- solid ratio 20 ∶ 1, concentration of alkaline ethanol was 2.60mL /100mL ( 25% ammonia /ethanol) , extraction time 50min, extraction twice.Under these conditions, the average purity of phosphatidylinositol was 58.86%, with its yield was 70.14%.