Abstract: The cashew nuts produced abundantly by Hainan were used to be the research object,the alkaline extraction and acid precipitation technology of extraction process was optimized with solid- to- liquid( S / L) ratio,solvent p H,extraction temperature and time by single- factor and response surface methodology designs. The results showed that the best experimental conditions were found to be extraction at 40 ℃ for 1.5 h using an extraction solvent at p H11 with S / L ratio of 1 ∶ 50( g / m L).Under the optimized conditions,the yield of protein was87.1% ± 1.05%.The cashew nuts protein extraction regression model was highly significant( R~2= 0.9406),with good fitting and could be used to predict protein extraction rate.