Abstract: Objective To analyze the serumlevel of soluble eggantigen(SEA)induced specific antibody IgG in or derto understand the dynamics of the IgG with PRO C MIX ED procedure in SAS.Methods Thirty female mice aged 6-8 weeks were divided into three groups:infection group(group A),the rapy group(group B),and reinfection grouop(group C).Ten cercarie/permice were used to infect the mice of group A and group B.Group B was treated with praziquantel at the dosage of 400 mg/kg 50 days after the infection.Group C was infected for the second time with 10 cercarie/per mice 70 days after the first infection.We used fiber micro tube to collect blood samples from angularvein of mice and preserve them at-20℃ frozen condition.A fterwards,we used enzyme linked mimuno sorbent a ssay(ELISA)to detect seruman tibody levels.Then we used PROC MIX ED procedure in SAS to analyze the fixed effect and ram dom effect of SEA induced spec ific an tibo dy IgG leve.l R esu lts There was no significant difference in IgG antibody at the time between 0 and 20 days a fter the infection.There was also no significant difference in IgG antibody at the time between 70 and 120 days a fter the infection.There were significant differences(P<0.0001)in IgG antibody at the time between 30 and 60 days after the infection.Conclusion The results present a dynamic change of specific antibody IgG induced by schisto somia sisjaponica SEA and coincides well with the biological observatio n.PRO CMIXED procedure could be adoted in the analysis of medical experiment data.