Based on a biomimetic conception, nano-hydroxyapatite (n-HA)/polyamide66 (PA66) composite scaffolds were prepared with anisotropic properties both in morphology and mechanical behavior. A novel improved thermally induced phase separation (TIPS) technique was developed to generate orientation-structured scaffolds for tissue engineering. The physiochemical, morphological, and mechanical properties of the resultant scaffolds were evaluated. According to the results, the improved TIPS method exhibited good processability and reproducibility and enabled the composite scaffolds to have a high content of inorganic fillers. The morphological study proved that the n-HA/PA66 scaffolds exhibited unidirectional microtubular architecture with high porosity (ca. 80-85%) and an optimal pore size ranging from 200 to 500 mu m. Besides, the effect of n-HA content on the morphology of the scaffolds was studied, and the results indicated that the obtained scaffolds presented an improvement in anisotropic morphology with increase of n-HA content. The anisotropy was also evaluated in the mechanical properties of the scaffolds, that is, the longitudinal compressive strength and modulus were similar to 1.5 times of the transverse ones. (C) 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 658-669, 2009