The effect of the pretreatment conditions on enzymatic digestibility was discussed with Bamboo (Sinocalamus affinis) Refiner mechanical pulp (RMP) as the feedstock soaking in two different solutions, ammonia and potassium hydroxide, ammonia and potassium phosphate. The optimum pretreatment conditions of ammonia and potassium hydroxide were determined as follows：reaction temperature 120℃, solid to liquid ratio (mass/volume)1:6 g/mL, pretreatment time 3.5h, ammonia charge 70%(g/g oven dry, the same below), potassium hydroxide charge 5%.Under such conditions, the recovery ratio of cellulose, hemicelluloses and the delignification ratio can reach 90.66%, 92.90 % and 41.05%, respectively. The reducing sugar yield and conversion yield of cellulose can attain 23.95% and 44.61% respectively under the condition of per gram of pretreatment feedstock loaded with 20 FPU after enzymatic hydrolysis for 24 h at acetic acid sodium buffer solution of pH 4.8 and reaction temperature 50℃.The conversion yield of cellulose can attain 56.95%, but the recovery ratio of cellulose can reach 74.59% with the method of ammonia and potassium phosphate. The loss of the cellulose ratio is larger than the ammonia and potassium hydroxide pretreatment method.