Hydroxyapatite is the main inorganic component of bones and teeth. In order to improve mechanical properties and surgical handiness of bioceramics, a plasticizing agent e.g. polysaccharide can be added. Chitosan is a polysaccharide with biological properties that make it an ideal component of bioceramics-based composites for medical application as bone substitute. In this study, biocompatibility of two types of novel krill chitosan-based composites was evaluated. In vitro experiments were carried out using human foetal osteoblast cell line. Cytotoxicity, cell adhesion, and bone ALP activity tests were performed to assess biocompatibility of the composites. Osteoblast growth on composites was observed using confocal microscope. Our results demonstrated that fabricated novel composites are non-toxic, are favorable to cell adhesion and growth, and provoke increase in b-ALP activity with time, thus inducing osteoblast differentiation. Based on this data composites have promising clinical potential as a bone defect filler in regenerative medicine. It is worth emphasizing that our work resulted in fabrication of flexible and surgical handy, bone substitutes that possess absolute biocompatibility with structural and mechanical properties similar to trabecular bone.