This paper describes the preparation and characterization of a three-dimensional, porous sponges made from alginate. The alginate solution was mixed with hydroxylapatite(HAp) to increase its mechanical properties and biocompatibility. The sponge was prepared by a three-step procedure: first gelation of the alginate solution to form a hydrogel with bivalent cations (such as Ca2+, Sr2+ and Ba2+), then freezing, and finally drying by lyophilization to produce a three-dimensional, porous sponge. The effects of quenching temperature, type and concentration of crossing linking agents on the structure and properties of scaffolds were investigated. The results demonstrate that the porous sponges not only have well interconnected pore structure, but also have well mechanical properties. In order to examine its biocompatibility, rat osteogenic sarcoma cell line (OGS) was seeded into the scaffolds. Using alginate sponges that serve as a template for tissue engineering has a potential use in the regeneration of bone tissue.