The biodegradability of cellulose fibers ,cotton, viscose, bamboo(viscose), Modal and Lyocell, was charactered by the changes of color,morphology, weight,mechanical properties,crystallinity, and chemical properties after buried in nature soil for a period of time. And the influences on biodegradability were discussed.After 90 days, the experimental results indicated that all five cellulose fibers experienced a rapid degradation.However,cotton, as the nature cellulose fiber, presented the fastest degradation rate .The sort of degradation rate was cotton>viscose>bamboo(viscose)>Modal>Lyocell.Analyses show the morphology and internal crystal structure has a significant influence on the biodegradability, and biodegradability of natural cellulose fiber is better than regenerated cellulose fiber, the substances residues in the regenerated?cellulose?fibers during the manufacturing processes decrease their biodegradability.