Quinoa is considered a nutritious food mainly due to its high protein content, and the balanced proportion of amino acids. In this study, quinoa protein isolate, mannose, xylose were grafting reacted at 65 ℃ with different proportions. Functional properties, the changes in the structure, anti-inflammatory, anti-proliferative activity in vitro were evaluated. The grafting degree, polyacrylamide gel electrophoresis analysis showed that Maillard reaction occurred between quinoa protein isolate and mannose and xylose. The structure and morphology of the reaction products have changed. Emulsification, water absorption capacity and fat absorption capacity of glycosylated compounds also increased significantly. When the proportion of quinoa protein isolates and monosaccharide was 2:1, modified protein has the best physical and chemical properties and biological activities.