Abstract: In this paper, a new analysis method for power divider is proposed. This method uses the reflection and isolation scattering parameters between any two isolated ports to strictly derive the constraint conditions expressed by the Y matrix that any two isolated ports should satisfy. The design process is proposed of power division circuit is designed first and then determine the isolation circuit, which guides the miniaturization design of the device. Compared with the traditional odd/ even mode method, this method provides more rigorous analysis process for asymmetric power dividers. This method is also applicable to the analysis of design problems of power dividers, orthogonal and 180° couplers with arbitrary port numbers, arbitrary terminal real impedances, and arbitrary power division ratios. Using this method, we made a power divider on a microstrip PCB (printed circuit board). By comparing theoretical calculations, full-wave simulations, and measurement results, the results show that the designed compact power divider has good performance.