A thermosensitive polymer can be held liquid before being injected to deliver living cells or therapeutic agents and formed monolithic gels when injected in vivo. In this study, chitosan-based thermosensitive hydrogels were prepared, characterized and the biocompatibility for culturing mice bone mesenchymal stem cells (BMSC) on 2D films and within 3D hydrogel were investigated. The gelation temperature and biocompatibility could be modulated by addition hydroxyethyl cellulose (HEC) to chitosan-glycerophosphate (CH-GP) formulation. The CH-GP-HEC liquid solution can turn into gel at body temperature and has highly compatible with BMSC. Therefore, the CH-GP-HEC gel could be used as an attractive injected in-situ forming scaffold for future applications of delivering biologically active therapeutics for tissue engineering filed.