Porous blocks of bioactive ceramics are a more preferable tissue substitute to replace and reconstruct the defected tissues in that their interconnective pores are beneficial to new tissue ingrowth. The most important specification requires the controlled interconnective pores with required mechanical strength. A novel chitin-gel-cast approach is utilized to prepare porous bioceramic blocks. In order to improve their interconnection of pores, several acids are selected to etch the windows between porous. Light microscope (LM) and Scanning electronic microscope (SEM) are used to investigate the etching effect on the windows and walls of porous blocks. The results show that the acid etching can improve the interconnection of porous blocks with slight decrease of compressive strength under carefully controlled process conditions.