Abstract: In this paper,the steady N-S equations in a rotating helical right angle coordinates are presented firstly.The flow in a rotating helical elliptical pipe is studied by using the method with which Dean studied the flow in a stationary curved circular pipe.The study indicates that the flow is affected by four parameters:Dean number D, parameter η, parameter σ and axial aspect ratio λ.The effects of different control parameters on flow behaviors are analyzed in detail.The results of this paper also indicate that the first order of torsion has no effect on the flow in the rotating helical circular pipe.