Abstracts: Two kinds of cellulose are added in concrete to investigate the influences of different cellulose dosages on workability, strength of mortar and impermeability of concrete. The micro-structure of concrete with cellulose is also studied. The results show that the workability of mortar is reduced with the cellulose dosage increased. The compressive and flexural strength of mortar with cellulose are lower than the mortar without cellulose in the age of 28-days, but the strength at the later has a little improved. The cellucose can obviously improve the impermeability of concrete, and the SEM morphology analysis shows that the cellulose can effect the hydration process of cement and improve the microporous structure of concrete.