The content of essential oil of Annona squamosa is 0.15 percent (fresh leaves) and of A. reticulata is 0.20 percent (fresh leaves). The compounds detected in the leaf oil of Annona squamosa and A. reticulata from Vietnam are listed in the table of the total 76 oil components, thirty five were identified in leaf oil of A. reticulata, that make up about 92.4 percent. The major constituent of the essential oil was beta-elemene (36.5 percent). This major compound was accompanied by lesser quantities of germacrene D (16.0 percent), beta-caryophyllene (5.3 percent), beta-bourbonene (4.7 percent), alpha-copaene (4.3 percent). Other compounds consist with amount lesser than 1.0 percent to trace.