Abstract: A variety of exhaust mixers with small tabs in comparison with a conventional annular exhaust mixer were tested at atmospheric pressure to study the effects of tab structure parameters-number and fix angles on the aerodynamic characteristics of the exhaust mixer system.The results showed that:Small tabs could enhance two flow mixing,distort downstream flowfield,increase entrainment,and improve system mixing uniformity,but the pressure loss coefficient of the system would increase a bit.Several tabs well distributed and alternately tilted inward and outward around the nozzle exit were more effective on the two flow mixing enhancement.