Based on the cake of camellia oleifera seeds as raw materials,the methanol as extraction agents,use quadratic general rotary unitized experimental design to optimize the process of ultrasonic-assisted extraction.Based on the single factor,solid-liquid ratio,extracting temperature and the time were selected as the test elements.The regression mathematics model with extraction efficiency of tea saponin as the target was established.The optimization extraction conditions was achieved through the results of variance analysis and mathematical model optimization.The results showed that the best condition for the ultrasonic-assisted extraction of the tea saponin is;solid-liquid ratio 1:9,temperature 50℃,extracting for 57mins.Under this condition,the tea saponin extraction efficiency can reach to 80.89%.