PURPOSE: The titled composition for a powder coating material, capable of giving a cured film having improved flexibility and impact resistance with the low foaming property without emitting a volatile content on curing, and prepard by incorporating a poly N-acyl cyclic urea compound as a curing agent with a compound having two or more active hydrogen atoms.

CONSTITUTION: A poly N-acyl cyclic urea compound, e.g. oxalylbis(N-tetramethylene)urea, expressed by formula I or II (R' is 4W11C bivalent aliphatic hydrocarbon, etc.; R is di-totetravalent organic group, etc.; n is an integer 2W4) as a curing agent is incorporated with a compound having two or more active hydrogen atoms, preferably vinyl polymer or polyester resin. Another curing agent, e.g. blocked polyisocyanate, may be added thereto if necessary. The vinyl polymer or polyester resin preferably have an OH value of 10W150KOHmg/g resin and a softening point of 80W150°C.