Abstract: A new formulation of biological floating granules of mosquito control was made through the process according to the ecological habits of mosquitoes and the characteristics of Bacillus sphaericus (BS-10) on mosquito control,with corn cob core granules as carrier and Bacillus sphaericus (BS-10) as active ingredient.After the experiment and model application, the granular formulation was proved to be highly effective.And 2 g per square meter of water gave an efficacy of higher than 95% mortalty of mosquito larvae.A long duration lasting for more than two weeks could be achieved.Its efficacy could be kept after 1 year storage under room temperature. Manufacture of the production of such granular formulations simple,and easy to apply. This formulation is an environment friendly product.