Adding whiskers to ceramic was a way that has been used to strengthen the ceramics matrix. For porous materials, strength of pore walls was an important factor for strength of the whole materials. Porous calcium phosphate ceramics were always used as scaffolds of bone tissue engineering because of their biocompatible and osteoconductibility. In this work, HA whiskers were born in the porous -TCP ceramic during in situ procedure. The HA whiskers with about 2m for length and 100nm for diameter were observed from SEM photographs of as-fabricated porous HA ceramics, and the phase content was determined by XRD.