In this study, the essential oils in Cunninghamia lanceolata heartwood were water-steam distilled, and their chemical components were analyzed by column chromatography and GC-MS, with their antimicrobial activity tested. The results showed that the essential oils content was 1.794-2.076 (w/w), and 47 peaks were separated. 27 compounds, accounted for 99% of crude essential oils, were identified. The essential oils had an obvious antimicrobial activity against Escherichia coli, Staphylococcus aureus, Bacillus sabtills and Salmonella typhi, and cedrol, occupying 76.27% of essential oils, was the major component with antimicrobial activity.