The essential oil from the leaves of Pseudocalymma alliaceum Sandw.was analyzed by GC-MS. The results indicated that there were twenty-seven peaks and seventeen compounds were identified.The identified compounds represented 93.15% of total content. The major constituents were phytol (54.33%), diallyl disulfide (13.31%),1-octen-3-ol(8.25%),(Z)-3-hexen-1-ol(4.10%),diallyl trisulfide (2.00%),butyl propenyl sulfide(1.91%), etc. The sulfur-containing compounds represented 18.79% of total content. The results provide the basic data for the comprehensive utilization of P.alliaceum leaf.