Abstract: Abstract：Objective To evaluate the biocompatibility of titanium alloy before and after casting by cell culture and MTT test. Methods Three kinds of titanium alloys before and after casting were processed into wafers whose diameter was 13.5 mm and thickness was 1 mm.Extracts were prepared for cell culture after cleaning and disinfection.Observe cell morphology and test the cells′ absorbance value in each group after culturing for 1,3 and 5 days. Results ①Cell absorbance value of C group which contained aluminum and vanadium was slightly lower than those of the other two groups no matter before or after casting（P>0.05）.②Cell absorbance values of three groups after casting were slightly lower than those before casting (P>0.05). Conclusions Casting has no effect on the biocompatibility of titanium alloys.It doesn′t affect clinical application.