Aim to find out if there is significant difference in the title of antibodies in the serum of O type blood populations in different regions in China by testing the level of antibody titles in O type blood across 11 cities. automatism microplate technique are used Statistics were made of the titles of IgM and IgG of anti-A(B) antibodies in O type blood serum of 440 samples, suggesting the title of IgM antibodies was relatively low, with 1:16 as the most frequent title; the title of IgG antibodies was relatively high, with 1:64 as the most frequent title. There are no significant difference in the level of antibodies between the 11 cities.