The influence of paramerters (diameter of die nozzle ,temperature of barrel,speed of screw,material moisture)of extrusion of maize with germ on the observed indexes (dextrinisation degree,extract content,fat,fermentable saccharide,total acid)and the optimum parameters of this extrusion system were studied. Experimental results indicate that if parameters of this extrusion system are quantified reasonably,the saccharification and filteration of wort which includes walt and extruded maize with germ as adjunct may go on successfully without adding any enzyme.