During　the　course　of　Adaptive　Active　Noise　Control　(AANC),　the　final　noise　canceling　effect　of　the　AANC　is　in　close　relationship　with　the　arrangements　of　error　sensors.　in　this　paper,　the　problems　of　optimizing　positions　of　error　sensors　have　been　investigated　by　using　the　Genetic　Algorithm　(GA),　and　are　difficult　to　be　solved　by　using　the　conventional　gradient　search　method.　The　computer　simulations　show　that　the　optimal　positions　found　by　the　GA　coincide　with　the　results　theoretically　calculated.