Abstract: Hydroxyapatite ceramics with controlled porosity and pore size were prepared by adding PMMA as pore-forming agent(PFA). Samples were prepared with total pore volumes changing from 20% to 50%.The pore structure,pore size distribution and characteristics were studied, and it was found that the hydroxyapatite ceramics with controlled-porosity could prepared by adding PMMA as PFA. As well, the factors influencing porosity and mechanical strength of porous ceramics were discussed.