The invention provides a surface modification method of vulcanized rubber or thermoplastic elastomer, which can provide excelent sliding property and repeatedly sliding durability and maintain sealing property without using high-priced self-lubricated resin. The invention relates to a surface modification mehtod, whose modification object is vulcanized rubber or thermoplastic elastomer, and the method comprises the following steps: process 1, surface irradiation of the modificed object with 300-400 nm LED light, thereby forming a polymerization trigger from the photosensitizer on the surface process 2, surface irradiation of the modificed object with 300-400 nm LED light, thereby carrying out free radical polymerization of free radical polymerized monomers using the polymerization trigger as starting point, and carrying out growth of the polymer chain on the surface of the modified object.
