The measurement method of evaporation residue of PVC gaskets was analyzed and studied based on area measurement method and mass measurement method, and the effect of sample shape and mass on the quantity of evaporation residue was discussed. The results showed that the quantity of evaporation residue based on area measurement method is greater than that of mass measurement method, and the quantity of evaporation residue of round-shape gaskets is greater than that of sheet-shape gaskets; sample mass shows great effect on the quantity of evaporation residue based on mass measurement method, but has little effect on that of evaporation residue based on area measurement method.