Objective To analyze and compare the chemical components of the volatile oil in different parts of Cryptotae-nia japonica .Methods Essential oils were extracted from the root ,stem ,leaf ,fruit of Cryptotaenia japonica through steam distillation .GC-MS analysis combined with Kovats retention index methods were used to analyze its main components .Results 28 peaks were separated and 28 compounds were identified from volatile oils from the root of Cryptotaenia japonica ,ac-counting for 86.66% of the total ,27 peaks were separated and 27 compounds were identified from volatile oils from stem of Cryptotaenia japonica ,accounting for 88 .01% of the total ,27 peaks were separated and 27 compounds were identified from volatile oils from leaves of Cryptotaenia japonica ,accounting for 94 .03% of the total ,26 peaks were separated and 26 com-pounds were identified from volatile oils from fruit of Cryptotaenia japonica ,accounting for 88 .32% of the total .35 kinds of volatile compounds were identified from the whole strain ,and the main components of each part of the volatile oil were sesquit-erpene compounds ,containing a small amount of monoterpenes .Among all the 35 compounds ,different parts of Cryptotaenia japonica share 22 compounds .Compounds 19 ,23 only exists in the volatile oil from the roots .Aromadendrene ,compound 25 , red myrrh alcohol only exists in the volatile oil from the fruit .So there is a certain difference in the types and quantity of the compounds .Conclusion The volatile oil of Cryptotaenia japonica contains many physiologically active substance .Take the whole plant as a medicine has its rationality ,which provide a scientific basis for the further research and development of Cryp-totaenia j aponica .