The aim of this study was to investigate bioactivities of 50% Chitin - hydroxyapatite (Chitin-H) compound and 50% Chitosan - hydroxyapatite (Chitosan-H) compound in canine bone. Ten healthy mongrel dogs (1-5 years old, 1.7 - 6.9 kg) were used in this study. These compounds had been transplanted into bilateral femur separately, and then the changes of femur were observed through the examinations of hemato-biochemical profiles, radiology, and histological profiles for 42 days. After 3 weeks, expanded radiolucent changes were observed in both areas transplanted the compounds. After 6 weeks, the area transplanted the Chitin-H compound did not observe any changes of bony tissue, while the area inserted the Chitosan-H compound was observed changes of increasing bone formation. In histological examination, infiltrations of inflammatory cells and bone absorptions were observed at both transplanted sites. However an increasing of active osteogenesis was observed at the transplanted site with Chitosan-H compound. In conclusion, Chitosan-H compound had an function of active osteogenesis as compared with Chitin-H compound. From this study, it is indicated that Chitosan-H compound would be used in dogs with severe bone defect.