The biocontrol effect of endophytic fungi Chaetomium globosum against rapeseed clubroot was studied in laboratory.Results showed that after irrigating spores suspension of C. globosum around rapeseed root,the activities of peroxidase,polyphenol oxidase and phenylalanine ammonia lyase were all obviously increased.When the spore suspension of C. globosum was inoculated by irrigation rapeseed rhizosphere soil,the disease incidence and disease index of rapeseed clubroot were significantly decreased.The control efficiency was 76.88%.The active compounds were isolated and purified from C. globosum culture by polarity gradient extraction,thin layer chromatography and HPLC. The active substances were identified as C16 sphingosine and phytosphingosine via LC-MS.The sphingosine obviously inhibited the germination of Plasmodiophora brassicae resting spores.MIC value of sphingosine was lower than 0.1 μg/mL.The antagonistic mechanisms of C. globosum to P. brassicae were confirmed as induced systemic resistance and secondary metabolites.