Abstract: In order to find out rule for sintering time to influence hydroxyapatite(HA) target, the powder of 99% pure hydroxyapatite was pressed to discal targets and the targets were sintered for 12 hour, 16 hour, 20 hour and 24 hour at 800℃ in argon ambience respectively. The targets stinered at different time were detected with X-ray diffractometer(XRD) and the X-ray photoelectron spectroscopy(XPS). The experimental result demonstrates sintering time did not influence on the composition and crystallinity of targets observably, but sintering time should influence on the ratio of Ca to P of targets. The ratio of Ca to P should increase when sintering time increase from 12 hour to 20 hour, but the ratio of Ca to P should decrease when sintering time increase from 20 hour to 24 hour. The hydroxyapatite target sintered for 20 hour at 800℃ should have the best biocompatibility and stability.

Key words: materials; hydroxyapatite；sintering time；ratio of Ca to P；biocompatibility