Abstract: Objective:The reliability of“The Standards of Skeletal Maturity of Hand and Wrist for Chinese-China 05”RUS-CHN method were reexamined in present.Methods:Under the conditions that readers were blinded to the age of the children and sex, the hand and wrist radiographs of 45children (skeletal age 2to 18years) were independently read by 13readers using China 05RUS-CHN method.The radiographs were re-read by same readers 30days later.The percentage agreement in ratings and the differences of skeletal age in repeating were estimated to evaluate the reliability.Results:It was found that intraobserver percentage agreement of ratings were 70.5% to 92.1% (mean 84.3%) , and the 95% confidence limits for a single reading were ±0.26year to ±0.49year for China 05 RUS-CHN;b) interobserver percentage agreement of ratings were 69.0% to 83.3% (mean 78.1%) , and the 95% confidence limits for a single reading were±0.35year to ±0.56year for China 05RUS-CHN. Conclusions:The present findings suggest that the reliability levels of skeletal age assessment were enhanced with repeatedly training and experience in using China 05RUS-CHN.The percentage agreement in ratings and the systematic and random error of skeletal age assessment should regularly be estimated for increasing quality work of practice.