[Objectives]  To increase the number of fungal biocontrol agents available for controlling the mealybugs Planococcus lilacinus and Phenacoccus solani. [Methods]  Fungi were isolated from fungus-infected mealybugs and their taxonomic statis, culture conditions and pathogenicity to P. lilacinus and P. solani were determined. [Results]  A strain of the entomopathogenic fungus LL-01 isolated from infected P. lilacinus was identified as Lecanicillium lecanii on the basis of rDNA-ITS, 18S rDNA and Nad1 gene sequence analysis. The optimal culture conditions for the growth and sporulation of this strain were 26 ℃, 6L︰18D, with fructose as a carbon source and casein as a nitrogen source. Under these conditions, the colony diameter and sporulation of the LL-01 strain after ten days cultivation were 4.66 cm and 4.16×10⁸ conidia/cm², respectively. The LC₅₀ values of this strain after 10 days for different instars of P. lilacinus and P. solani were 9.80×10⁴- 9.17×10⁵ conidia/mL and 5.00×10⁴-5.30×10⁵ conidia/mL, respectively. Mortality was 84.09%-97.62% and 89.89%-98.85%, respectively and the LT₅₀ values for a dose of 1×10⁸ conidia/mL were 3.70-5.84 d and 3.48-5.14 d, respectively. The peaks of protease and chitinase activity of the fungal strain were 19.44 U/mL and 15.01 U/mL, respectively, on the fifth day post-infection, and the peak lipase value was 7.68 U/mL recorded on the sixth day post-infection. [Conclusion]  The fungul strain L. lecanii LL-01 has fast growth and high sporulation, and is strongly pathogenic to P. lilacinus and P. solani.