Abstract: Choosing Chongqing Osmanthus fragrans leaves as raw- materials, by using cellulase extract polysaccharide from Osmanthus fragrans leaves, optimizing extract technology through response surface method ( RSM) could improve the extraction yield of Osmanthus fragrans leaves polysaccharide. The best extraction condition was liquid solid ratio of 8∶1, temperature of 50℃, extraction time of 60 min, and enzyme volume of1.2mg / mL. Under this condition, the Osmanthus fragrans leaves polysaccharide extract yield was up to 13.21%, and the DPPH free radical scavenging experiment revealed the high antioxidant activity of Osmanthus fragrans leaves polysaccharide.Reference basis and theory support could be provided to some relative manufactories when the reasonable process was decided through the study of the best extraction condition of Osmanthus fragrans leaves polysaccharide.