Abstract: A novel micro-strip three-way power divider is presented.The power divider is formed by ten λg/4 transmission lines and two isolation resistances.Multiport network method is adopted to analyze the scatter characteristic of the divider and the approximate expression is acquired.Then two power dividers which power dividing ratios are 1︰1︰1 and 1︰2︰1 respectively is obtained by using numeric optimization and simulation.The simulated and measured results coincide and indicate that the thereinafter performances could be achieved, that the return loss of each port is better than -16 dB，the isolation of each port is better than 20 dB，the error of the various output power ratios of each port is less than±0.5 dB， and the relative bandwidth is more than 25%.The power divider has compact structure，and it could be well applied to monolithic microwave integrated circuit(MMIC) and radio frequency integrated circuit(RFIC).