Objective:To analyze the main chemical constituents of volatile oil from barks of Juglans mandshurica.Method:Volatile oil from barks of Juglans mandshurica was extracted by vapour-vapour extraction method（VVE） and steam distillation method（SD）

respectively.These constituents separated from the volatile oil were identified by GC-MS

and the relative percentage of these constituents were calculated by area normalization method.Result:34 components in volatile oil extracted by VVE were separated and identified

which took 97.76% of the total volatile oil;19 constituents in volatile oil extracted by SD were also separated and identified

and their relative percentage was 69.06% of the total volatile oil.Conclusion:The constituents and content of volatile oil extracted by VVE and SD exhibited significant differences

these results provided experimental basis for understanding the constituents and further exploitation of volatile oil from barks of J.mandshurica.