To provide an adhesive composition having a sufficient adhesive property even when being reheated and stuck after being dried and a solvent was removed, and capable of sticking resin sheet foam on the curved surface of resin moldings without detachment in their interface, to provide resin sheet foam having the above adhesive composition layer and to provide a method for adhesion using the above adhesive composition.

This adhesive composition contains (A) a linear saturated polymer resin having a number average molecular weight 25,000-30,000 and the glass transition temperature -12°C to -18°C, (B) a triisocyanate and (C) chlorinated polypropylene. It is pref. that the constituent B and C are included in a quantity of 2-7 pts.wt. and 2-10 pts.wt. respectively, based on 100 pts.wt. constituent A and, if needed, 5-10 pts.wt. tackifier such as petroleum resin and 0.5-5 pts.wt. solvent having the higher boiling point can be included.