a-amylase is an industrially important enzyme that catalyses the hydrolysis of starch to yield products like glucose and maltose. Optimization of a-amylase production by isolate Bacillus amyloliquefaciens S8TS was done using technique of solid state fermentation (SSF). Different types of agro-industrial substrates (wheat straw, rice husk, wheat porridge, wheat bran) were used for the production of a-amylase but wheat bran gave highest a-amylase activity (3.50 ?0.088 U/mg) when moisten with 10 ml diluent (D-3) at pH 7.0, temperature 37oC with 10% vegetative inoculum after 72 h of incubation.