Abstract: Serum IgG, IgA and IgM levels of 91 patients with alveolar echinococcosis and 83 patients with cystic echinococcosis were compared with 104 healthy adults as controls by single radial immunodiffusion. The mean IgG, IgA and IgM concentrations in patients with alveolar echinococcosis and the mean IgG and IgM levels in patients with cystic echinococcosis were found to be significantly higher than those of the normal controls.The mean IgG, IgA and IgM levels in patients with alveococcosis were 510 ± 413.06, 389.45±433.42 and 313.48 ±255.19, while those in cystococcosis were 308.36±339.24, 329.61±319 and 266.68± 255.68 respectively.The geometric mean of IgG and IgM levels in patients with alveococcosis was 1.67 and 1.25 times that in cystococcosis. 76.9% of alveococcosis patients had IgG levels reaching 200 IU/ml or above, being significantly higher than that in the cystic hydati-dosis (50.6%). 93.4% of alveolar echinococcosis cases showed elevated IgM levels up to 100IU/ml or more, being also significantly higher than that of cystic echinococcosis cases (78.3).Statistically, there was significant correlation between IgG concentration and ELISA antibody titre.