Abstract: A kind of pear juice with high diet fiber was developed by adding inulin.The formula of inulin pear juice was optimized with the methods of single factor experiment,Box- Behnken( BB) and orthogonal experiment combining sensory evaluation. And free radical scavenging capacity and the dietary fiber content of inulin pear juice were investigated by DPPH and gravimetric analysis methods.The results showed that the higher juice yield of pear treated by 0.05% of pectinase,and the optimization formula of inulin pear juice including 40% of pear juice,7.0% of sugar,0.15% of citric acid,2.99% of inulin,0.15% of carboxymethyl cellulose sodium( CMC- Na),0.10% of xanthan gum and 0.15% of sodium alginate.The IC50 of free radical scavenging of the inulin pear juice was 2.64%and the content of diet fibre was 4.98%,and the two indexes were both higher than the control,which indicated that the diet fibre content and anti- oxidation of inulin pear juice were improved by adding inulin.