Microcrystalline cellulise was prepared successfully from cellulose was prepared successfully from cellulose of rice straw by selective hydrolytic method in dilute hydrochloride acid. Effects of percentages of hydrochloride acid, duration of hydrolysis process on productivity and coloration of the Microcrystalline cellulose collected were studied. The product was standardized and complied with it is standard. The product may be applied for producing tablets.