P<0.05）。The effects of the amount of enzyme added, ultrasonic power, enzymolysis temperature, pH value and time on the extraction yield of polysaccharides from longan pulp were optimized by response surface methodology. The optimal technological conditions of extraction by ultrasonic and cellulase were determined, then regression mathematical model was established. The optimal technological parameters are as follows: longan pulp with water ratio is 8.47%, cellulase additive ratios is 2000U/g, ultrasonic power is 250W, enzymolysis temperature is 55 ℃, enzymolysis pH value is 5.0, enzymolysis time is 60min, under such conditions, the polysaccharides extraction rate is 38.71%. This result approximated to the value of mathematical model calculated.