Porous hydroxyapatite (HA) ceramic scaffolds are extensively used to induct the tissue growth for bone repair and replacement, and serve functions to support the adhesion, transfer, proliferation and differentiation of cells. Highly porous structure is always expected for its positive effect on the bone regeneration in vivo, nevertheless high porosity always accompanies a decrease in strength of the HA ceramic scaffolds. Therefore, it is significant to improve the strength of the HA ceramic scaffolds with highly interconnected porosity so that they are more suitable in clinic applications. The aim of this study is to investigate the effect of starting materials on mechanical property of final scaffold in order to optimize the preparation process. In this work, three starting HA particles with different morphologies are used to prepare highly porous HA ceramic scaffolds by the polymer impregnation approach in the same preparation process. The phase composition, microstructure and mechanical properties of the sintered porous HA scaffolds are investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM) and compressive test. The experimental results show that the particle morphologies have influence on the slurry viscosity and further affect the coating amount on the sponge. The porous HA ceramics fabricated by spherical HA particle hold the highest compressive strength than the other two HA scaffolds for better sintering property. It is an effectively method to improve the mechanical property of porous HA ceramic scaffolds by optimizing the starting particle morphology.