Polyester polyols were synthesized by using each one mole of sebacic acid, isophthalic acid, ethylene glycol, and neopentyl glycol. The synthesized polyol had 56.6 mg KOH/g of hydroxy value and 1980 g/mole of molecular weight. From FT-IR structure analysis of polyester polyol, Hydroxy group(-OH) was observed around 3600 $cm^{-1}$, -CH shoulder of sebacic acid at 2950 $cm^{-1}$, carbony group of ester around 1730 $cm^{-1}$, and benzene ring of isophthalic ring was represented at 1600 $cm^{-1}$, 740 $cm^{-1}$. In case of polyurethane, hydroxy peak was showed at 3600 $cm^{-1}$, and -NH group around 3300 $cm^{-1}$, 1530 $cm^{-1}$. From $^1H$ NMR measurement of polyester polyol, it was found that sebacic acid was represented at 1.3, 1.5, 2.1 ppm, isophthalic acid at 7.3, 8.1, 8.7 ppm, ethylene glycol at 4.2 ppm, and neopentyl glycol at 0.8, 3.2, 3.9 ppm, respectively. In the polyurethane, it is almost the same as spectrum of polyester polyol, but showed very week peak at 7 ppm by benzene ring of toluene diisocyanate.