In the survey of the endophytic fungi associated with Camptotheca acuminata grown at the Qinba Mountainous regions,we obtained 42 fungal isolates.HPLC screening of extracts of these strains showed the peak position of the strain M-20(retention time,5.314 min) was very close to that of the authentic camptothecin(5.453 mim).HPLC-MS analysis indicated the fungal camptothecin produced a fragment peak M+H+ at m/z 349.4,and the reference camptothecin yielded M+H+ at m/z 349.2,demonstrating the isolate M-20 produced camptothecin with a yield of 233.3 μg/L.The strain M-20 was identified as Xylaria sp.according to its sequence assays and morphological characteristics as well.