The aroma components of geranium oil were analyzed by GC/MS, and the peak area normalization method was used to calculate the relative content of each component. With the mass spectrometry library search, 61 compounds which account for 86.217% in the aroma components of geranium, were identified by using reference literature retention index. The cis(trans)-isomers were confirmed by using retention index, and the accuracy of compound qualitative analysis in natural flavor was improved. The aroma of the key aroma compositions of the geranium oil (Citronellol, Geraniol, Citronellyl formate, Menthone, Geranyl formate, Isomenthone, Geranyl tiglate, Rose oxide, Geranyl butyrate, et al) was determined.