The effect of the screen blade turbine impeller on power requirement in stirred mixer was investigated. Power data were measured by the dynanomic method. The range of the impeller rotational speed was from 120 rpm to 1,540 rpm. In an unbaffled system, power data for the three types （of the impeller） are much the same. In a baffled system, power data for the screen blade turbines are much less than the flat blade turbine.