Sugar cane bagasse waste sourced from Okinawa, Japan, was regenerated into transparent and flexible cellulose hydrogel film. The biocompatibility of the hydrogel films was evaluated by in vivo test with mice. Cellulose fibers purified from sugar cane baggase were dissolved in lithium chloride/N,N-dimethylacetamide (LiCl/DMAc), and physically cross-linked cellulose fibers could change into hydrogel film by a phase inversion process of the cellulose solution under ethanol vapor. To evaluate biocompatibility, cellulose hydrogel films were implanted in the intraperitoneal of mice for 4 weeks. The results showed small influence of the implanted hydrogel films on the growth of mice. It was seen that no inflammation reaction in the intraperitoneal was observed by post-mortem examination. Furthermore, the molecular weight of cellulose was somewhat decreased from 5.7 x 10(5) to 3.9 x 10(5) in 3-4 weeks, meaning that the cellulose segments were biodegradable. However, viscoelastic measurement revealed that the hydrogel films kept their mechanical strength in the living body. Consequently, the cellulose hydrogel films regenerated from sugar cane baggsse waste showed not only acceptable biocompatibility but also durability in the body.