PURPOSE: To provide a hot-melt gasket compsn. with excellent adhesiveness to a coating surface and little surface tack aftercooling by incorporating a reactive elastomer consisting of a specified styrene block copolymer and a process oil softening agent in a specified wt. ratio.

CONSTITUTION: A hot-melt gasket compsn. is prepd. by mixing 50-100 pts.wt. reactive elastomer (A) consisting of a carboxyl-modified styrene/ethylene/ butylene/styrene block copolymer or a styrene/butadiene/styrene block copolymer and 50-250 pts.wt. softening agent (B) consisting of a process oil as the essential ingredients. As this compsn. exhibits excellent adhesiveness to an object such as a metal and suppressed surface tackiness after being cooled and solidified, adhesion to a member on the opposite side of the object hardly occurs and in addition, sag hardly occurs when it is used in a high-temp. environment and the shape recovery is good.