To elucidate the effect of heavy metals on enzymes production and the characteristics of enzymatic degradation in the process of biodegradation of polycyclic aromatic hydrocarbons (PAHs) by Bacillus sp. P1, enzyme variations (the content and composition of proteinase, the activities of catechol 2,3-dioxygenase in crude enzymes and enzymatic degradation ability) in the process of phenanthrene degradation were investigated in the presence of Cd(II). The results showed that Cd (II) would inhibit enzyme productions and enzymatic degradation. As Cd(II) increased from 0 to 150 mg/L, the amount of extracellular and intracellular proteinase (absolute integrated optical density analyzed by Gelpro) decreased from 8.37×106, 1.54×107 to 5.49×106, 6.01×106, respectively. As Cd(II) increased from 0 to 300 mg/L, the activities of catechol 2,3-dioxygenase in extracellular enzymes (EE) and intracellular enzymes (IE) decreased from 266.96 to 38.93 U/mg, 886.30 to 290.26 U/mg, respectively. The degradation rates of Phenanthrene (PHE) by EE and IE decreased from 79.86% to 64.59%, 87.96% to 74.83%, respectively. These results suggest that Cd (II) can cause enzyme variation, thus affecting the phenanthrene biodegradation by Bacillus sp. P1.