Abstract: Celtis sinensis is an important native tree species, which has the advantages of straight trunk, large crown width and anti-smoke and dust, and is widely used in the planting of street trees, and has ornamental value, but its development and utilization is limited because of the slow germination rate of C. sinensis. In the experiments, the petroleum ether phase, ether phase, ethyl acetate phase and methanol phase were separated from the extract of seed embryo and seed shells of C. sinensis seeds by systematic solvent method, and the biological activity of these five phases was detected by the germination test of cabbage seeds. At the same time, gas chromatography-mass spectrometry(GC-MS) combined whether there were endogenous inhibitors and their relative contents in the seeds, and to explore the relationship between the inhibitors and seed dormancy, in order to provide references for the causes of seed dormancy and the methods of releasing dormancy. The results showed that each separated phase of C. sinensis seeds had a certain inhibitory effect on the germination of cabbage seeds, among which ethyl acetate phase and ether phase were the strongest, followed by methanol phase and petroleum ether phase, respectively. Combined with the results of GC-MS and biological detection, it was found that the main components of endogenous inhibitors were organic acids: acetic acid, palmitic acid, and ester substances: dimethyl phthalate. And some benzene substances: butylated hydroxytoluene, may also have an inhibitory effect.