Objective To investigate the age differences and its reasons of severe complications in the application of bronchoscope in China.Methods According to the 11 criteria of severe complications defined by Jin Faguang,all the papers about severe complications in the application of bronchoscope published before December 2005 were searched through CNKI.The reported cases were divided into group 1 (before 1985),group 2 (between 1986 and 1995),and group 3 (between 1996 and 2005).The chi-square test was used to calculate the P value and compare.Results Ten papers were eligible for the criteria,including three papers in group 1,three papers in group 2,and four papers in group 3.Results showed that the incidence rate of severe complications was 0.497％ (267/53 742) in group 1,0.291 ％ (243/83 458) in group 2,0.941％ (248/26 333) in group 3.Except mortality rate (x2 =2.867,P =0.238) and pneumothorax rate (x2=1.926,P =0.382),the incidence rates of severe complications in the application of bronchoscope were of significant difference among different ages in other nine complications and overall complication (x2=181.344,P =0.000).Except that the incidence rate of complication of larynx,trachea,bronchus spasm in group 1 and tuberculosis in group 2 were the highest among the three groups,incidence rates of other complications in group 3 were the highest.Conclusions From the late last century to the beginning of this century,the extensive application of new intracavity technology in trachea and bronchus may be the main reason that causes the remarkable increase of severe complications in group 3.This also shows the importance of standardizing the intervene endoscope operation.For example,in Europe especially German,rigid bronchoscopy is layed stress on in the treatment of air way stricture threatening life,which remains to discuss.