Abstract: The effect of different substrate concentrations on the growth of Paecilomyces lilacinus “NH-PL-03”was studied.The results show that the substrate concentration has a significant effect on the growth of Paecilomyces lilacinus. To some degrees, a lower substrate concentration (C+N=0.015g/mL) is good for sporulation, the sporulation reaches the peak value of 69.20 million/mL at 8d, and a higher concentration (C+N=0.045g/mL) benefits the biomass growth and toxic outcome, the maximal dry matter weight of culture liquid of 0.82g(each 50mL) occurs at 10d, the toxic result to Ditylenchus destructor is 52.30% at 8d. The highest substrate concentration (C+N=0.135g/mL) shows obvious inhibitting effect on the growth of Paecilomyces lilacinus, whose dry matter weight and sporulation are 0.23g and 15.10 million/mL at 10d.