The methyl ester contents of biodiesels produced from these oil feedstocks were determined by GC technique. The gas chromatograph of Agilent 6890N that equipped with a flame ionization detector and a capillary column of crosslinked polyethylene glycol (HP-INNOWax, 25 m x 0.20 mm x0.2 μm). The gas chromatograph oven waskept at 200ºC for 5 min. The carrier gas was helium at a flow rate of 0.5 ml/min. The analysis was carried out by injecting 1 μL of sample solution into the gas chromatograph. The n-heptane was used as the solvent for preparing the sample solution. Each methyl ester in the sample was identified by comparing its retention time with the retention time of the standard of the methyl ester of FFAs. Methyl heptadecanoate was used as the internal standard for the methyl ester content determination