In the present study Response surface methodology (RSM) was used to investigate the combined effect of relevant process variables to enhance the production of amylase under submerged fermentation by Bacillus amyloliquifaciens SH8.The process variables included pH, temperature, inoculum size, incubation days and substrate concentration.A 54 factorial central composite design (CCD) using response surface methodology (RSM) was employed to obtain interaction between the process variables and optimizing amylase titers.Total 54 experiments were carried out in shake flask and a three dimensional response surface was generated to determine the effect of process variables on amylase production.The optimal calculated values of tested variables for maximal production of amylase were: pH 5, temperature 45°C, inoculum size 5%, incubation day of 5 and substrate concentration of 0.60% with 16.07 IU/ml of amylase activity