Total IgG and IgG4 subclass antibody were investigated in serum of neurocysticercosis patients who were divided into four groups.The first group consisted of parasitological and clinically confirmed patients before treatment.The second,third and fourth groups comprised treated patients after 1～3,4～6 and 7～9 therapeutic courses respectively(Each therapeutic course includes 10～14 days)*.241 serum samples from these four groups were detected with EITB using lentil-lectin affinity purified antigens for total IgG and IgG4.36 sera from healthy individuals were used as negative control.We also detected 27 sera from patients of echinococcosis and clonorchiosis by the same method.Compared to negative control the total IgG and IgG4 subclass antibody levels in four different groups were respectively 96.3% and 97.5% for the lst group;93.3% and 78.6% for the 2ed;88.0% and 38.0% for the 3rd;86.1% and 13.9% for the 4th.There was no significant difference for the total IgG among these four groups(P>0.01).In contrast,the levels of IgG4 antibodies in the post-treatment patients were lower than that of the before-treatment patients.The positive rate of IgG4 antibody in symptomatic post-treatment patients is 77.0% but in asymptomatic post-treatment patients is only 21.3%(P<0.001).None of the antigens recognized by IgG was unique to the four groups.GP42 and GP24 were the most common bands recognized by many patients for IgG,but in the latter two groups,IgG4 distinctively recognized low molecular weight antigen of 18kD and 13kD.36 sera from healthy individuals were all negative.The positive rate of total IgG antibody in 27 sera from heterologous infections is 7.5%,in contrast,IgG4 antibody of these sera were all negative.These observation confirmed that IgG4 is an important diagnostic parameter for cure of human neurocysticercosis.