This study was by mean of agar gel diffusion and immunoelectrophoresis and 7216, 1897 and B.t. galleae strains of Bacillus thuringiensis were used as contrasta. The results were that 187 and 1897 each showed three prcipitation lines, two of which appeared in cross reaction, one didn't. 7216 showed two lines, B.t.g.—three lines and they didn't show cross reaction with 187 or 1897. It suggest that 187 and 1897 from same serotypes (H)each showed a specific antigen components, and the toxicity to insects is associated with the antigenic characteri...