The degradation effects and characters of Pseudomonas Pseudoalcaligenes with PVA(0588, 1788, 2088, 1750, 1799) were studied. The degradation rates of different types of PVA were measured with UV2900 ultraviolet spectrophotometer. The molecular weight and degree of alcoholysis，PVA concentration, concentration of inoculated strains, rotary speed effects on PVA degradation rate were researched as well. The optimal conditions were determined as: when the culture temperature was 30℃，with the treating time of 72 h, rotary speed of 180rad/min, the concentration of PVA as 0.5 g/L and the concentration of pseudomonas pseudoalcaligenes as 4.0%, the ratio of degradation could reach as high as 90.15%.