Abstract: Template database is the key to radar automation target recognition based on High Resolution Range Profile (HRRP). Because of the complicate electromagnetic scattering in real target and background clutter, the traditional method based on the template of average HRRP does not has a good performance sometimes. The geometric structure of HRRPs on the unit hypersphere is analyzed, and the templates of cluster center and affinity sphere are built. Based on the affinity sphere, the new distance measure is defined. Finally a new recognition method is proposed based on the affinity among HRRPs. The experiment results based on MSTAR data demonstrate that the proposed method achieves a good engineering performance.