Abstract: Narrowband radar provides poor range resolution because of the limit of the bandwidth, and it is usually used to targets tracking，detection and motional parameters extraction. For the rotating targets, narrowband radar can achieve both range and cross resolution by tomography through long time irradiation. This imaging method possesses the advantage as it has no band limitation. The paper interprets the mechanism of the narrowband imaging based on the tomography, deduces both cross and range resolution for the narrowband imaging and gives the target imaging results using the simulated narrowband return waves. The experiment results tested by the scattering target model show the feasibility of the narrowband imaging.