Objective:To evaluate the feasibility of the injectable thermosetting microspheres-chitosan/glycerophosphate(M-C/GP) hydrogel as a new embolism meterial of aneurysms. Methods:Chitosan/glycerophosphate solution(1:7) and sodium alginate microspheres were mixed in different volume ratios. The hydrogel of microspheres-chitosan/glycerophosphate(M-C/GP) was prepared by ultrasonic emulsification and ice bath stirring. The pH,colloidization time and mechanic strength of the hydrogel were detected respectively to determine the best ratio. The intracatheter manipulation and intratumoral gelation of the M-C/GP hydrogel was evaluated by embolizing aneurysm models. The tissue compatibility of the M-C/GP hydrogel was evaluated by embolizing rabbit ear arteries. Results:When the ratio of M-C/GP was 1:2 at pH 7.28,the colloidization time was 2.5 minutes and the mechanic strength could reach 14 kPa at the compression strain of 20%,with the peak of 25 kPa. In the experiment of embolizing aneurysm models in vitro,the phenomenon of M-C/GP overflow was not observed during the embolizing,nor the phenomenon of M-C/GP colloghore during the drawing microcatheter. In the experiment of embolizing rabbit ear arteries in vivo,tissue rejection was not happened. A few of inflammatory cells were found in the vessel walls 3 days after embolizing rabbit ear arteries. The number of inflammatory cells was gradually increased in the peak in 1 week,and significantly reduced in 3 weeks. Conclusion:Preliminarily,M-C/GP can be a kind of new non-adhesion tissue engineering materials,with suitable pH,right colloidization time,better mechanical strength,intracatheter manipulation,intratumoral gelation and tissue compatibility,which can be used to embolize aneurysms.