Inorganic-organic composites could mimic the composite nature of real bone and combine the toughness of a polymer with the strength of an inorganic one to generate bioactive materials with improved mechanical properties and degradation profiles. In this paper, HAp/Col porous scaffold was prepared based on inorganic nano-sized hydoroxyapatite (nHAp) and organic collagen (Col) by solvent casting/particulate leaching. Sodium chloride (NaCl) and ethyl cellulose (EC) were performed as the porogenic agent and binding agent, respectively. The physical, chemical and biodegradation property of this scaffold were investigated in vitro and its co-culture with cells was also studied. The results showed that the scaffold had good mechanical property with the average pore sizes about 150 μm and porosities as high as 75%. This nHAp/Col porous scaffold had no cytotoxicity to mouse pre-osteoblast MC3T3-E1 and the content of alkaline phosphatase (ALP) was ascending with the extension of culture time. The results of mineralization indicated that HAp/Col scaffold could promote the proliferation, differentiation and biological mineralization of MC3T3-E1.