Long-chain fatty acid cellulose esters (FACE) were synthesized by the acid chloride-pyridine reaction with different degrees of substitution (DS). The hydrolyzed soybean oil was used as unsaturated fatty acids, its unsaturation degree, and composition were analyzed by H-1 and C-13 NMR methods. The chemical structures of FACE were confirmed by solid-state C-13 NMR, and substitution reaction of fatty acid chloride on cellulose were analyzed by IR spectroscopy. FACE(s) are insoluble in common organic solvents, such as benzene, toluene, THF, etc., at refluxing temperature. As the DS increased, the tensile strength of extruded FACE films decreased, but elongation increased.