Abstract: The samples consisted of 120 Chinese male sterna of known age (19- 74)4 Observations were made at three characters of sternum (Facies articularis of manubrium-corpus sterni, Facies articularis of incisurae constales, Substantia of corpus sterni dorsalis). Based on the changes in these areas, the sterna were separated into six phases (l-VI).
Phase I Facies articularis incisurae costales is not complete, assumed V-shape. Margo articularis of manubrium-corpus is not complete. Facies dorsalis of corpus sterni is smooth(mean age 19-25).
Phase II Margo articularis of incisurae costales is complete. A few processes can be seen on the margo articularis of manubrium-corpus. Facies dorsalis of corpus sterni is the same as phase I (mean age 25-28).
Phase III A few processes can be seen on the margo articularis of incisurae costales. The processes become more and more marked on the margo articularis of manubrium-corpus. Facies dorsalis of corpus sterni is the same as phase I (mean age 30-34).
Phase IV The processes become more and more marked on the margo articularis of incisurae costales. Margo articularis of manubrium- corpus becomes thicker. Substantia corpus sterni dorsalis decreases slightly in density (mean age 35-40).
Phase V There are some breakages on the margo articularis of incisurae costales. Ecstrophy of margo articularis of manubrium-corpus can be seen and there are a few breakages on the margin. Facies dorsalis of corpus sterni is the same as phase IV (mean age 45-53).
Phase VI The margo articularis of incisurae costales becomes saw-shaped. The breakages become more and more marked on the margo articularis of manubrium-corpus. Substantia of corpus sterni dorsalis becomes spongy(mean age 56-74).
Statistical analysis revealed that the features chosen to delineate the phases are valid predictors of age. This study has shown that the charactcrs of sternum can provide an accurate estimation of Chinese male with age span of 19 -74.

Key words: Sternum; Age determination