Abstract: Objective To investigate the present status of antibiotic use in paediatrics'infectious diseases in Changchun and guide the rational use of antibiotics.Methods 700 cases of infectious diseases of childen from Changchun were randomly selected for a retro-spective investigation from 2003 to 2006.To analyze the combined treatment status,variety,frequency,average days of medication and the relationship between antibiotic use with susceptibility test and WBC.Results From 2003 to 2006,the rates of antibiotic use were 95%,100%,99%,100%.The most use frequencies of antibiotic were cefuroxime (37%),cefuroxime(32%),cephathiamidin(25%),cephathiamidin(33%).The most days of antibiotic use were cefuroxime (4.5d),cefuroxime(4.5d),cefotaxim/sulbactam(4.7d),cefotaxim/sulbactam(6.7d).The rates of the antibiotic use within susceptibility test were 8.4%,12%,12.7%,11%.The rates of the antibiotic use within normal limits of WBC were 54.2%,63%,67.7%,71%.Conclusion The antibiotic use of paediatrics'infectious diseases is unitary and irrationalitical in Changchun.The use of antibiotic needs more standardization.