The present invention is a method for manufacturing a phosphorylcholine group-containing polysaccharide wherein the aldehyde derivative-containing compound obtained by the oxidative ring-opening reaction of glycerophosphorylcholine is added to a polysaccharide containing amino groups as well as a new polysaccharide having phosphorylcholine groups obtained from this manufacturing method. The object of the present invention is to provide a phosphorylcholine group-containing polysaccharide that is superior in biocompatibility and moisture retention, and is useful as a polymer material for medical use, as well as a simple method of manufacturing it. The polysaccharide of the present invention is utilized, for example, in artificial organs, biomembranes, coating agents for medical tools, drug delivery, and in cosmetics.