Previous research on cellulose-based materials focused mainly on the characterization and industrial scale applications. The main purpose of this study is to determine the in vivo biocompatibility and biodegradation behavior of three different type nanocellulose suspensions: cellulose nano-crystal (CNC), cellulose nano-fiber (CNF) and (2, 2, 6, 6-tetramethylpiperidine-1-oxyl)-oxidized cellulose nano-fibrils (TTOCNF). All nanocellulose suspensions were adjusted to closely match physiological conditions (pH 7.4-8, 36°C) and were characterized Transmission electron microscopy to check the nano-particles size structure. The nano-cellulose solutions were then check for the cells toxicity by MTT assay with fibroblast cells (L292) and rat bone marrow Mesenchymal stem cells (rBMSc), after that nanocellulose was subcutaneously injected into rats for in-vivo studies. Tissue samples containing the injected suspensions were extracted 1, 2, 4 and 12 weeks after injection and processed for histological examination. Fibrous tissue formation, blood vessel density and residual area of nanocellulose were measured using ImageJ software, immunohistochemistry was used to confirm the host immune response to nanocellulose injected. Nanocellulose exhibited a chemical and physical structure that was suitable for use as a biomaterial. Histomorphometry results demonstrated the biocompatible and biodegradable behavior of nano-cellulose. Injectable nanocellulose can be used as an implantation material in the body. The results support the use of CNC only in skin or soft tissue applications, which will fast remove materials within 1 month. Results also suggested using CNF for anti-adhesive applications and the TTOCNF for bone applications such as injectable bone substitute or 3-D scaffold for bone regeneration.