Abstract:Eight essential oils from Citrus bergamia Risso & Poit., Citrus limon L., Citrus sinensis (L.) Osbeck, Citrus grandis (L.) Osbeck, Citrus reticulata Blanco, Citrus medica L. leaves and fruits were analyzed qualitatively and quantitatively by means of GC / MS. Their chemical constituents have been identified. Because of the different constitutents and contents, the odour of the essential oils possessed different characteristics. Moreover, this paper discussed the influence on the quality and the odour from the terpenes group, the carevol and carvone group, citronellal, menthadienol group, and provid-ed the scientific bases for the application of Citrus medica and Citrus grandis oils.