Abstract: Information Geometry is a set of system info originated from study on the geometry properties of statistical manifold which offers one kind of new thinking and method to the radar signal processing problems.A new kind of view to radar target detection problem is given based on information geometry theory in this article,simultaneously,information geometry method to radar target detection is also proposed by defining the distance between two distributions on statistical manifold.The information geometry method to radar target detection detercts target by comparing the distance between the distribution estimated by the oberservation datas and two hypothetical distribution when target exists or not,translating radar target detection problem into geometry problem on statistical manifold which is easy to be accomplished.Finally,detection performance of information geometry method and likelihood ratio detector is compared by simulations.