Abstract: The Euler/Kirchhoff method is adopted to calculate the far field noise of UH-1H rotor,and the calculated results are compared with the measured data.The effect of rotor blade tip shape on high speed rotor noise is investigated.The results show that,with the decreasing of airfoil thickness near the blade tip or the increasing of the taper ratio near the blade tip and the sweep of the blade tip, the high speed rotor noise can be reduced to some extent.