OBJECTIVE： To analyze the difference of volatile oil components from the leaves of Clausena lansium and Clausena excavata. METHODS： The volatile oil was extracted from the leaves of C. lansium and C. excavata by steam distillation. GC-MS method was adopted to analyze volatile oil to obtain TIC. After mass spectra scanning of the chromatographic peaks in the TIC diagram by HPMSD chemical workstation， chemical components of volatile oil in 2 kinds of samples were identified by retrieving and comparing mass spectrum database NIST Version 1.7. The peak area normalization method was used to calculate the relative mass fraction of each component. RESULTS： A total of 43 and 31 kinds of components were identified in volatile oil from the leaves of C. lansium and C. excavata； total relative mass fractions were 97.59％ and 98.57％. Relative mass fractions of 19 and 18 components in volatile oil from the leaves of C. lansium and C. excavata were more than 1％， mainly being sesquiterpenoids. Relative mass fractions of 7 and 5 components in volatile oil from the leaves of C. lansium and C. excavata were more than 5％； the volatile components in volatile oil from the leaves of C. lansium were mainly （-）-spatol （12.35％） and （E）-5-{（1R，3R，6S）-2，3-dimethyltricyclic [2.2.1.02，6] heptane-3-yl}-2-methyl pentane-2-enol （14.70％）； those from the leaves of C. excavata were mainly （E）-sesquihydrated betuline （24.94％） and 1-（1， 5-dimethy-4-hexenyl）-4-methyl-benzene （16.15％）. A total of 4 components were found in volatile oil from the leaves of C. lansium and C. excavata， mainly being α-humulene， （E）-5-{（1R，3R，6S）-2，3-dimethyltricyclic [2.2.1.02，6] heptane-3-yl}-2-methylpentaeryl-2-enol， caryophyllene oxide and （-）-spatol； the content differences of them were not significant. CONCLUSIONS： The components of volatile oils from the leaves of C. lansium and C. excavata are basically similar However， the composition and comtent of specific components are quiet different and can not substituted for each other.