Plastic is considering the mother industry to hundreds of products but the lack of biodegradability focused attention on a potentially huge environmental pollution problem. Aliphatic polyesters, poly (ε-caprolactone) (PCL) are biodegradable by microorganisms, which possess cutinolytic enzymes. Alternaria alternata-ST01, showed both high growth and enzyme activity on yeast glucose malt broth (YGMB) medium fed with PCL film than on YGMB medium without PCL film under shaking and stationary conditions. The hydrolytic enzyme activity of the culture on ρ-nitrophenylpalmitate indicated the fungus possesses cutinase. This activity was confirmed by the degradation of PCL film, which reached the maximum (72.09%) and (56.49%) within a short time (15 days) under shaking and stationary conditions respectively. Interestingly, in the absence of carbohydrate source in the YM medium, the fungus depends on PCL and the degradation was stimulated to record 93.33% on the 15^th day. The non-significant relationship was recorded between the enzyme and protein production and the pH value. Scanning electron microscope showed cracks and erosion on the PCL film surface treated with A. alternata-ST01. These results suggest that the extracellular cutinase of Alternaria alternata-ST01 may be useful for the biological degradation of plastic wastes.