Biodegradable porous nanocomposite scaffolds of poly(lactide-co-glycolide)(PLGA) and L-lactic acid(LAc) oligomer surface-grafted hydroxyapatite nanoparticles(op-HA) with a honeycomb monolith structure were fabricated with the single-phase solution freeze-drying method.The effects of different freezing temperatures on the properties of the scaffolds,such as microstructures,compressive strength,cell penetration and cell proliferation were studied.The highly porous and well interconnected scaffolds with a tunable pore structure were obtained.The effect of different freezing temperature(4℃,-20℃,-80℃and -196℃) was investigated in relation to the scaffold morphology,the porosity varied from 91.2%to 83.0%and the average pore diameter varied from(167.2±62.6)μm to(11.9±4.2)μm while theσ_(10) increased significantly.The cell proliferation were decreased and associated with the above-mentioned properties.Uniform distribution of op-HA particles and homogeneous roughness of pore wall surfaces were found in the 4℃frozen scaffold.The 4℃frozen scaffold exhibited better cell penetration and increased cell proliferation because of its larger pore size,higher porosity and interconnection.The microstructures described here provide a new approach for the design and fabrication of op-HA/PLGA based scaffold materials with potentially broad applicability for replacement of bone defects.