Abstract: The amplitudes and phases of radiating elements of nonuniform array antenna could be controlled in order to achieve special shaped beam. There was little discussion about the influence of the nonuniformity to the length of microstrip line in the conventional design. In the paper,a simulation method to obtain the equivalent parameters of microstrip patch is presented. Comprehensively considering with nonuniformity's effect,a 32 series fed microstrip antenna array at X band giving the synthesis of a cosecant square pattern is designed. And by use of the software CST,the antenna array is simulated and measured. The results agreed with the requirements.