Abstract: OBJECTIVE To study the molecular serum osteopontin expression in patients with asthma in children,so as to provide the basis for clinical practice.METHODS A total of 89 cases of children with asthma treated in hospital from Dec.2014 to Dec.2016 were selected and their data were analyzed,who were treated as test group.The same period 69 patients has healthy result in health check as control group,using reverse transcription polymerase chain reaction（RT-PCR）agarose electrophoresis technology to give analysis for two groups’ children serum osteopontin expression,asthma prevalence,pathogenic bacteria and influencing factors.RESULTS The experimental group was measured after OPN,extaxin and immunoglobulins IgM,IgG,IgA index,which were significantly higher than control group（P＜0.05）.There were 35 cases of nosocomial infections in experimental group,and the infection rate was 39.3%.A total of 47 strains of pathogen were successfully isolated from infected patients,including the top three pathogens Staphylococcus aureus,Escherichia coli and Pseudomonas aeruginosa,which accounted for 34.1%,17.0%and 14.9%.The incidence of infection in children with asthma and hemoglobin levels,T4/T8 and whether AGT difference had no significant difference,but which had close relation with absolute neutrophil count（P＜0.05）.CONCLUSION Children with asthma serum osteopontin expression of molecules is relatively high,which has close relation to decreasing produce of angiogenesis in body′s bone marrow and hematopoietic,so the pathogens and drug test should be strengthened to reduce infection rates.