Abrupt performance degradation caused by face pose variations has been one of the bottlenecks for practical face recognition applications. This paper presents a practical pose normalization technique by using a generic 3D face model as a priori. The 3D face model greatly facilitates the setup of the correspondence between non-frontal and frontal face images, which can be exploited as a priori to transform a non-frontal face image, with known pose but very sparse correspondence with the generic face model, into a frontal one by warping techniques. Our experiments have shown that the proposed method can greatly improve the recognition performance of the current face recognition methods without pose normalization.