Simulated bioslurry remediation of PAHs contaminated soil was carried out. Three strains of fungi isolated from petroleum-contaminated soils were inoculated into paddy soils different in application rate of phenanthrene and phthalic acid, to investigate their effects of co-metabolic degradation of B[a]P therein. Results show that in natural soils, some native microorganisms were able to degrade B[a]P and addition of low molecular weight PAHs-phenanthrene increased, degradation rate of B[a]P in the soil. The effect was greater when the application rate of phenanthrene was 100 mg kg-1 than when it was 200 mg kg-1. But the addition of phthalic acid did not show much effect. In sterilized soils, degradation of B[a]P in soils was hardly observed. However, inoculation of Penicillium stimulated degradation of B[a]P in all the three treatments, i.e. phenanthrene at 100 mg kg-1, phenanthrene at 200 mg kg- and phthalic acid, but only in the treatment of phenanthrene at 100 mg kg-1 the effect was significant. Inoculation of Aspergillus niger also showed similar effect, which, however, was inhibited by the presence of phenanthrene and phthalic acid in the soil. White-rot fungus could effectively degrade B[a]P, but high concentration of phenanthrene inhibited its effect in the soils, and phthalic acid was neither an optimal co- substrates of white-rot fungus in degrading B[a]P in paddy soils.