In order to investigate influence of sintering time on hydroxyapatite target, the hydroxyapatite powder with 99% purity is pressed into disc-shaped targets, and the targets are sintered for 12, 16, 20 and 24 h at 800°C in a argon ambience, respectively. Hydroxyapatite targets with different sintering time are detected with X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS). Results show that sintering time has no obvious influence on the crystallinity and composition of hydroxyapatite targets, but it has significant influence on the ratio of Ca to P. The ratio of Ca to P increases when the sintering time increases from 12 h to 20 h, but the ratio decreases when the sintering time increases from 20 h to 24 h. The hydroxyapatite target sintered for 20 h at 800°C has better biocompatibility and stability.