OBJECTIVE：To establish a metho d for simultaneous determinat ion of α-pinene，β-pinene，myrcene，limonene， γ-terpinene and α-terpineol in volatile oil from Citrus medica . METHODS ：GC-QAMS method was adopted. The determination was performed on Agilent DB- 17 capillary column. Flame ionization detector was adopted with nitrogen as carrier gas （purity 99.999％） at the flow rate of 0.5 mL/min. The flow rate of nitrogen （make-up gas ）was 25 mL/min，the flow rate of hydrogen was 30 mL/min， and the flow rate of air was 400 mL/min. The inlet temperature was 250 ℃，and the detector temperature was 280 ℃（programmed temperature），and injection volume was 0.5 μL with split ratio of 35 ∶ 1. Using limonene as internal reference ，relative correction factors of α-pinene，β-pinene，myrcene and γ-terpinene were calculated. The contents of 4 components in the samples were calculated according to the relative correction factors. The results were compared between QAMS and internal standard method （ISM，using dodecane as internal substance ，6 components to be determined ）. RESULTS ：The linear range of α-pinene，β-pinene， myrcene，limonene，γ-terpinene and α-terpineol were 0.030 5-0.213 8，0.066 6-0.466 0，0.021 8-0.152 3，0.765 2-5.356 4，0.387 3- 2.710 8，0.034 2-0.239 6 mg/mL（all r＞0.999）. The limits of detection were 4.82，7.89，4.01，4.54，5.53，2.47 µg/mL，and the limits of quantification were 15.34，25.91，13.69，15.70，18.68，8.36 µg/mL，respectively. RSDs of precision ，repeatability and stability tests （24 h）were all less than 2％. The average recovery rates were 96.08％，97.48％，100.90％，101.22％，100.54％， 95.84％（all RSD ＜3％，n＝6）. The average relative correction factors of α-pinene，β-pinene，myrcene and γ-terpinene were 0.997 8， 1.530 7，0.952 4 and 1.025 5 （all RSD ＜1％）. The contents of α-pinene，β-pinene，myrcene，limonene，γ-terpinene and α-terpineol by ISM were 3.296 9-20.994 1，11.300 6-39.440 9，3.684 2-11.291 4，174.857 8-511.611 8，0-285.127 3，0-48.858 6 mg/g， respectively. The contents of α-pinene，β-pinene，myrcene and γ-terpinene determined by QAMS were 3.296 8-20.994 0，11.300 3- 39.439 7，3.684 1-11.291 1，0-285.126 6 mg/g，respectively. Relative content errors of 4 components as α-pinene determined by 2 methods were all less than 1％ . CONCLUSIONS ： The Δ 基金项目：四川省科技厅应用基础研究项目（No.2021YJ0114）； established GC-QAMS method is simple ，rapid，accurate and 泸州市重点科技项目 [No.2011-S-31（3/3）]；合江县人民政府—西南医 科大学战略合作项目（No.2018-HJXNYD-2） repeatable，and can be used for quantitative analysis and ＊硕士研究生 。研究方向 ：中药制备工艺及质量评价 。电话： quality control of volatile oil from C. medica . 0830-3162291。E-mail：493359958@qq.com