Abstract: Objective:To observe the clinical efficacy of lactulose combined with live combined Bacillus subtilis and Enterococcus faecium granules with multivitamines(Mamiai)in neonatal jaundice therapy and explore its therapeutic mechanism.Methods:One hundred and twenty cases of neonatal jaundice were randomly divided into three groups,blue-ray therapy was used in control group;in group A,Mamiai was added on the basis of the control group,and in group B,lactulose combined with Mamiai was added on the basis of the control group.Results:Compared with group A,the effective rate in group B was improved(P0.05).Compared with control group,neonatal blood total bilirubin content was significantly lower in group A and group B after 6 days treatment(P0.01).Compared with group A,neonatal blood total bilirubin content in group B was lower(P0.05).Conclusions:Lactulose combined with Mamiai reduces serum bilirubin level through two different mechanisms,the efficacy for treatment of neonatal jaundice was reliable,safe,and worthy of clinical use.