In order to study the secondary metabolites of the endophytic fungus from the Euphorbia trucalli L.， the endophytic fungus Cytospora sp. L2 from Euphorbia trucalli L. was isolated and subjected to solid fermentation， and the extracts from the solid fermentation were separated and purified by using modern separation methods such as silica gel and HPLC. A total of 10 compounds were obtained. The compounds were identified as six sterol compounds、two dimeric alkyls aromatic、one butenolide and one ketone derivative by nuclear magnetic spectrum analysis and other methods. The compounds were identified as dankasterones A （1）， 6β - hydroxystigmast - 4 - en - 3 - one （2）， isocyathisterol （3）， 6β - hydroxy - ergosta - 4，7，22 - trien - 3 - one （4）， （24R） - ergosta - 4，6，8（14），22 - tetraene - 3 - one （5）， stigmast - 4 - en - 3 - one （6）， integracin A （7）， integracin B （8）， methyl 2，5 - dihydro - 4 - hydroxy - 5 - oxo - 3 - phenyl - 2 - furanpropanoate （9）， 4 - methoxy - 5 - methoxycarbonyl - 6 - propyl - 2 - pyrone （10）. Among them， compounds 1， 3， 5， 6， 9， and 10 were isolated from Cytospora sp. for the first time. In vitro antibacterial activity of the isolated compounds was determined by the double broth dilution method. The results showed that compounds 1 — 10 had weak inhibitory effects on Staphylococcus aureus， Staphylococcus epidermidis， Pseudomonas syringae pv. Tabaci and Ralstonia solanacearum.