Sphingolipids recently attract more attentions because of their distinctiveness on structures and expected functions. Liquid chromatography-mass spectrometry is one of the most powerful methods for the identification of chemical structures of sphingolipids. Glucosylceramides prepared from various foodstuffs including rice are generally used for functional foods and their structures are quite different from mammals. For structural analysis of glucosylceramides by LC-MS/MS, the typical signals which are characteristic for the sphingoid base moieties can be obtained as product ions. Using this method for rice and maize, glucosylceramides containing 4,8-sphingadienine (d18:2) acylated to hydroxy-fatty acids were detected as the predominant molecules. In addition, the presence of the triene type of sphingoid base (sphingatrienine, d18:3) in rice and maize was also emphasized.