Titanium and its alloys have been applied widely in hard tissue replaceme nts of human body.Many methods were d eveloped in order to improve their surface bioactivity,including physical methods,chemical methods and electrochemi cal methods.The surface bioactivity method of titanium and its alloys are reviewed in present paper.The processing and bioactivity mechanism of every method are introduced,and the advantages and disadvantages of those methods are also presented.Co mparing with physical methods,chem ical methods have more ad-vantages as follows:simple equipme nt and process,uniform coatings on c omplex surface,and the similar stru cture and compositions of coatings to those of natural bone.For chemical methods,it is necessary t o enhance the efficiency and the bond ing strength between coatings and substrates.And the effect of lon g-term implantation and the bioactivity theory of chemical methods are d emanded to research deeply.