PURPOSE: To obtain the title composition which will not cause a coating film to become sticky, has excellent resistance to heat and discoloration, and enables sealing with an excellent appearance of a coating, by incorporating specified stabilizer and plasticizer each in a specified amount into a sealing composition of vinyl chloride resin base.

CONSTITUTION: A sealing composition comprises a vinyl chloride resin, a filler, a stabilizer, a plasticizer, and an additive, wherein the stabilizer comprises an epoxy stabilizer in an amount of 1W3wt.% based on the total composition, and the plasticizer comprises a heat-resistant plasticizer (e.g., a trimellitate or pyromellitate) in an amount of 6W10wt.% based on the total composition. This composition will not inhibit the curing reaction of a coating material applied on the top thereof and therefore will not cause the coating film to become sticky it has excellent resistance to heat and discoloration; it can ensure the sealing of a joint area of, e.g., automobile body to thereby prevent rusting over a long period of time.