Objective To improve the selection of flying cadets of the Air Force of People′s Liberation Army of China ( PLAAF) by analyzing the differences of medical identification of lumbar spondylolysis between PLAAF and the US Air Force ( USAF) .Methods Flight crew who had been checked for lumbar spondylolysis during hospitalization at the Air Force General Hospital between 2013 and 2015 were chosen.The results of their medical identification were compaired according to PLAAF and USAF Medical Standards Directory, and their differences and possible reasons were analyzed accordingly.Results The qualified rate of PLAAF was about 85%, which was very close to the standards of USAF, but the difference was not of any statistical significance(P>0.05).Conclusion The standards of our medical identification of lumbar spondylolysis was similar to those of USAF, suggesting that the selection of flying cadets can be improved.