To define the activity and optimize the determination conditions of the cell wall degrading enzymes from asparagus stem blight pathogen, the activities of 7 cell wall degrading enzymes were determined by the 3,5-dinitrosalicylic acid (DNS) method,the induced effects of different substrates were compared,and the determination conditions for 3 main enzymes were optimized in 3 aspects, i.e. temperature, time and pH value. The results revealed that in the 7 cell wall degrading enzymes the activity of polygalacturonase (PG) was the most vigorous,followed by polymethylgalacturonase (PMG) and endo-β-1,4-glucanase (Cx), whereas the other 4 enzymes were of lower activity. In the 3 main enzymes, 1% CMC was the better induced substrate for Cx and 1% pectin was the better for PG and PMG. In regarding to reaction temperature,it was found that the best reaction temperature for Cx was 50℃ and the best for PG and PMG was 50-60℃ and 60℃, respectively. In regarding to reaction time,it was found that 50 min was more suitable for Cx, whereas 60 min was more suitable for PG and PMG. In regarding to pH value,it was found that pH 4.0 was more suitable for Cx and PG, whereas pH 8.0 was more suitable for PMG.