In this work, Box-Behnken design (BBD) was used to study the effect of liquid: solid ratio, cellulase concentration and Reaction time on the extraction of Jili polysaccharide from fruits of Tribulus terrestris L. Regression analysis was performed on the data obtained. The most relevant variable was solid: liquid ratio. The coefficient determination (R2) was good for the second-order model. Liquid: solid ratio of 24:1 (v/w), cellulase concentration of 2.0% and reaction time of 2.90h were found to be optimal for crude polysaccharides extraction from fruits of Tribulus terrestris L. By means of additional experiments, the adequacy of this model is confirmed