Abstract: A bacteriophage, GP-1 of Bacillus thuringiensis, with unique morphology and structure was isolated from the lytic fermentation liquor of Bacillus thuringiensis at Wuhan Microbial Pesticides Factory. Examination by JEM-100C electron microscope revealed that each phage has a long, six-sided head with short tails and a platelike collar structure with 8-10 appendages attached to the base of the head．The 8-10 appendages can greatly enhance the adsorption of the phage to the surface of the host and provide structural evidence for the further study of the relationships between this phage and its host． SDS polyacrylamide gel electrophoresis indicated that this phage has one major protein band，MW=58 892 D，one sub-major protein band and seven minor protein bands. These results indicate that nine kinds of proteins comprise the protein content of phage GP-1.

Key words: Bacillus thuringiensis, bacteriophages, morphology, protein