This study is to clarify the pathways of the transesterification of vegetable oil by applying NMR to the identification of intermediates in the transesterification reaction. Results showed that the significant methanolysis product was sn-1,3-diglycerides in diglycerides, and sn-2-monoglycerides was not found. These analytical results suggest that the methanolysis reaction may occur easily at the sn-2-position for both sn-tri- and sn-1,2-diglycerides. (c) 2006 Elsevier Ltd. All rights reserved.