The hydrolysis trials of produce microcrystalline cellulose from cotton linter ethnaol pulp by hydrochloric were investigated. Based on 23 factorial design, fifteen operations were performed by varying S/L, T and t (S/L: solid to liquor ratio, T: hydrolysis temperature, t: hydrolysis time). The charecteristic of product was analyzed by X-RD, SEM and laser granularity distributing apparatus, and compared with commercial MCC. The experimental results indicated that MCC yield and particle size were influenced significantly by those factors. The optimal hydrolysis conditions was S/L=1:7, T=60°C and t=40min, which can resulted MCC yield of 75.3% and size of 21.21µm. Crystallinity of MCC is 63.96% and displayed as rod-shape.