Objective To prepare a new injectable carbonated hydroxyapatite cement（CHC） which can set in situ and has porous configuration. Methods To prepare an in situ setting porous CHC（PCHC）, the 0.35% P-chitosan（PC） were added to make injectable PCHC(IPCHC). And the biocompatibility, PH value, time of solidify, mechanical property, chemical component, molecular structure, porous configuration, injectability and anti-washout ability were tested. Results 0.35%PC as a adjuvant was added to pore agent to prepare IPCHC. The porosity character and its injectability can be controlled by adjustment of the component. The test results demonstrate that the self-setting composition of this cement is carbonated hydroxyapatite, which is similar with natural cancellous bone. The porosity is 37.2% with interconnect pores; the setting time is 12 to 16 minutes, which is suitable for surgical application; the compressive strength is 4.3±2.6 Mpa, which is equal to that of cancellous bone; the cytotoxicity tests show an excellent biocompatibility; the concentration of CO32- is 5.6%, which is close to that of natural bone hydroxyapatite; the injection index of IPCHC is 95.13%±1.11%, which is significantly higher than that of PCHC(68.78％±2.19％); and IPCHC has good anti-washout ability. Conclusion Adding 0.35% PC to the liquid phase ofthe cement can improve its injectability greatly, and obtain a good antiwashout result. The IPCHC is useful to reconstruct nonloading bone defects in miniinvasive surgery, especially for the blooding site.