OBJECTIVE： To establish GC-MS fingerprint of volatile oil from Citrus aurantium.  METHODS： GC-MS method was adopted. The determination was performed on RTX-5MS capillary column with injector temperature of 250 ℃， high pure helium as carrier gas（≥99.999％）， flow rate of 1.0 mL/min， split ratio of 10 ∶ 1， and sample size of 1 μL （temperature programming）. Mass spectrum condition included electron bombardment ion source， ion source temperature of 230 ℃， detector temperature of 250 ℃， 3 min solvent delay， scanning range of m/z 35-550. GC-MS chromatograms of 21 batches of volatile oil samples were determined using Laurene as reference. The similarity of them was evaluated by using TCM Chromatographic Fingerprint Similarity Evaluation System （2004 A edition）， and common peak was determined. The components of common peak were determined by LC Solution 2 mass database （NIST05.LIB and NIST05s.LIB）. Relative content of common peak was determined with area normalization. RESULTS： There were 20 common peaks in GC-MS chromatograms of 21 batches of volatile oil samples， and the similarity was higher than 0.90. After validation， GC-MS chromatograms of 21 batches of volatile oil samples were in good agreement with control fingerprint. The main constituents of the volatile oil of C. aurantium were Limonene，Terpinene， Laurene and D-Cadinene. CONCLUSIONS： Established fingerprint can provide reference for identification and quality evaluation of volatile oil of C. aurantium.