Abstract: A crystalline polyester resin derived from the reaction between a prepolymer and trimellitic anhydride in an amount of less than 10 wt % of the prepolymer where prepolymer as an intermediate product formed from the reaction between an alcohol mixture containing at least 40 mole % ethylene glycol and at least 30 mol % neopentyl glycol, and an acid mixture containing terephthalic acid or dimethyl terephthalate of at least 40 mole % and a linear dicarboxylic acid, or between an alcohol mixture containing 100 wt % terephthalic acid or dimethyl terephthalate. The crystalline polyester resin is very suitable for use in powder coating compositions and has a hyodroxyl number of 20 to 100, an average molecular weight of 1000 to 3500 and a melt viscosity at 160.degree. C. of 500 to 4000 cps as well as the characteristics of dense, regular, and repetitive structure.