The invention belongs to the field of biological medicine, provides a new application of rose polysaccharides, and particularly relates to an application of the rose polysaccharides in preparation of drugs for treatment of Parkinson's disease.Water extraction-alcohol precipitation method is adopted for extracting the rose polysaccharides which can dramatically repress the expression of Alpha- synuclein.The rose polysaccharides have prominent therapeutical effects for caenorhabditis elegans Parkinson's disease pathological model, which hints that the rose polysaccharides have the potential to treat the Parkinson's disease, and can be applied in preparation of the drugs for treatment of the Parkinson's disease as well as in preparation of health care products for preventing and treating the Parkinson's disease in an aided manner.