The main objective of this research was to determine the reliability of sex identification. From the study of sternum morphology between female and male in Thai population. Thirty sternums of cadavers ages ranging from 20-80 years old were used in this study. Eight measurements were determined with unknown bone sex. Each bone was verified later and found that 15 males and 15 females. T-test and discriminant analysis was required to transform the variables measurement with SPSS programs. P value less than 0.05 was considered significant difference. Corpus sterni width at first sternebra (CSW_s1) was the most accuracy percent values for sex identification at 86.7% of reliability in both sexes. The average area of sternum in male was larger than female at 5872.71 mm³ and 4721.09 mm³, respectively. This result showed that sternum can be used for sex determination in forensic identifications and useful for forensic cases in the future.