The ultrasonic-assisted extraction process of total flavonoids from the leaves of Ziziphus jujuba var.spinosa was studied.Based on the experiment of single factor,the mathematical regression model was established about the dependent variable(extraction yield of total flavonoids) and independent variables(ratio of liquid to solid,ethanol concentration,extraction power and extraction tine) through Box-Benhnken center composite design and response surface methodology.The optimum extraction conditions were as follow∶ratio of liquid to solid of 42.00∶1,ethanol concentration of 60.10%,extraction power of 240 W and extraction time of 36.50 min.Under these conditions,the practical yield of total flavonoids reached to 5.382%,which was consistent with the predicated yield of total flavonoids of 5.407%.