Abstract: Objective To explore the prevalence,mechanism and dissemination of β-lactam resistant streptococcus pneumoniae isolates in Nanjing area.Methods A collection of 130 strains of streptococcus pneumoniae isolated from seven teaching hospitals in Nanjing between 2010 and 2012 were included in this study.MICs of 14 common antibiotics were determined by agar dilution test. pbp1A、pbp2B、pbp2X genes were amplified.All the isolates were analyzed by pbp fingertyping to e-valuate their gene relateness. Results The resistance rates of clinical isolates to penicillin, cefuroxime ,cefotaxime ,cefepime ,ceftiaxone ,amoxicillin and meropenem were 5 1 .5 % ,6 9 .2 % , 17.7%,12.3%,3.1%,6.2%,16.9% respectively.The penicillin resistant rate in children was higher than that in adult.A good correlation had been found between penicillin and cefuroxime, cefepime,amoxicillin.5 isolates exhibited type A1-B1-X1 in molecular typing might be the same clone.Conclusion The penicillin resistant rate in children is high,a small range of clone dissemina-tion is found in Nanjing.