Abstract: The distribution of turbulent intensity in the wide and narrow symmetrical planes of the jets from rectangular nozzles was experimentally investigated with hot-wire apparatus.The results show that the turbulent intensity decreases radially,and increases when AR(aspect ratio=W/H,W,nozzle width,H,nozzle height) of nozzle exits is smaller than 8,but decreases slightly when AR is bigger than 8.In the axis line,turbulent intensity increases slowly.The distributions are the same both in wide and narrow symmetrical planes,and the magnitude increases with AR,but decreases as AR is bigger than 8.