Abstract: A new phenanthrene degrading strain, Pseudomonas mendocina CGMCC 1.766, was screened out. The kinetics of cell growth, phenanthrene consumption, and the dynamic changes of the key enzyme activities during degradation were also investigated. In the culture system under initial phenanthrene concentration of 100mg/L, the addition of salicylic acid increased the degradation rates of phenanthrene, while the supplement of glucose reduced the degradation rates.