Abstract: Objective To compare the concentration of teeth DNA extracted by three different pretreatment methods and to explore a simple, economical and practical pretreatment method with high concentration of extracted DNA from teeth. Methods A total number of 21 molars were collected from 7 corpses. The pretreatment of 3 molars from each individual was randomly performed by tooth crumb method, ball-milling method and liquid nitrogen milling method and 50 mg tooth crumb was weight and DNA was extracted by AutoMate ExpressTM forensic DNA extraction system. Subsequently, the concentration of DNA and corresponding STR genotyping of three methods were compared. Results The DNA concentration extracted by tooth crumb method, ball-milling method and liquid nitrogen milling method was 0.055 6-1.989 1 ng/μL, 0.036 6-1.175 6 ng/μL and 0.037 8-1.249 0 ng/μL, respectively. The DNA concentration obtained by tooth crumb method was higher （P＜0.05） and the success rate of STR genotyping was high. Conclusion Combined with AutoMate ExpressTM forensic DNA extraction system, tooth crumb method is an efficient and feasible method to extract DNA from teeth, which can be applied in forensic practice.

Key words: forensic genetics, DNA, tooth, extraction, pretreatment