Abstract: Objective To observe the efficacy of lienal polypeptide injection combined with conventional therapy in treatment of children with recurrent respiratory infection and their influence on immune function.Methods A total of 128 children with recurrent respiratory infection were randomly divided into observation group and control group.Control group was given conventional therapy.On the basis of control group,observation group was given additional lienal polypeptide injection.All the children were followed up for 6 months,and the occurrence of respiratory infection was recorded.The changes of IgA,IgM,IgG and CD3 +,CD4 +,CDs +,CD4 +/CDs + were observed.Results The total effective rate of the observation group was significantly higher than the control group (P ＜ 0.05).After treatment,the IgA,IgM and IgG levels of observation group increased significantly (P ＜ 0.05)while control group had no significant change (P ＞ 0.05).The CD3 +,CD4 +,CD4 +/CDs + of observation group increased significantly and CDs + decreased significantly after treatment (P ＜ 0.05),while control group had no significant change (P ＞ 0.05).Conclusion On the basis of conventional therapy,lienal polypeptide injection can improve the therapeutic effect and enhance the immune function in children with recurrent respiratory infection.