Eight kinds of larger steric hindrance L-amino acid esters were synthesized by direct esterification of L-amino acid and isopropanol or isobutylalcohol with strong acidic cation resin as catalyst under microwave irradiation. The results showed that the esterification was greatly accelerated under microwave irradiation with 50~70% yields of these esters reached. The reaction time was substantially shorten to 1/48~1/72, especially for the reactant with higher polarity compared with conventional heating method. The structures of these esters were characterized by 1HNMR and IR. However, the influence of reaction conditions such as power, time of microwave irradiation and heating type on esterification was discussed.