Abstract: Objective The influence on age estimation by comparing the differences between left and right side development of osteophiphysis.Methods27osteophiphysis development indexes in the X-ray films of6major joints and pelvises in130male juveniles were Cbserved.The positions and levels of difference between left and right side development of osteophiphysis were compared.The male juvenile age by re - gression equation according to left side and right side were estimated respectively.Results In76cases,the age estimation results are the same for both sides.In47cases,the difference between left and right side is less than6months.In7cases,the difference is between6and12months.The error of94.6%age estimation is within6months.The differences between left and right osteophiphysis development are often found in proximal humerus,distal radius,distal ulna and crista iliaca.Conclusion The subtle differ - ence between left and right osteophiphysis development has no influence on age estimation.

Key words: osteophiphysis, differences between left side&right side, age estimation, juvenile