To investigate the compounds produced by the endophytic fungus Penicillium crustosum from Ophiocordyceps sinensis and their antibacterial activities,16 compounds were isolated and purified by reversed-phase silica gel column chromatography,MCI column chromatography,preparative HPLC,and other methods.Their structures were elucidated on the basis of NMR and MS spectroscopic evidences.The compounds were identified as Ac-L-Leu-L-Pro-OCH₃（1）,(E)-3-benzylidene-4-methyl-3,4-dihydro-1H-benzo［e］［1,4］diazepine-2,5-dione（2）,(Z)-3-benzylidene-4-methyl-3,4-dihydro-1H-benzo［e］［1,4］diazepine-2,5-dione（3）,cyclopenin（4）,(3S)-1,4-benzodiazepine-2,5-diones（5）,O-acetyl-β-paxitriol（6）,roquefortine C（7）,isoroquefortine C（8）,aflaquinolone G（9）,3-hydroxy-4-phenylquinolin-2(1H)-one（10）,viridicatol（11）,cyclo(Pro-Leu)（12）,N-(phenylmethyl) carbamic acid (13),(5S,6R,7S,8R)-5-amino-(2Z,4Z)-1,2,3-trihydroxybuta-2,4-dienyloxy-pentane-6,7,8,9-tetraol (14),2′,4′-dihydroxy-3′,5′-dimethylacetophenone (15), and conidiogenone B (16).The compounds isolated are mainly benzodiazepines,indole diterpenes and quinolone alkaloids.Compounds 1 and 2 were isolated as new natural products,and compounds 1-4,6,9,12-14 and 16 were isolated from this strain for the first time.