The received signal model of polarization sensitive array is presented under array mutual-coupling condition,then mutual coupling error is decomposed of orthogonal-array-element-factor-error and array-factor-error,which represent signal polarizational information error and spatial information error respectively.Under array mutual-coupling condition,we give the mathematical expressions of some important filtering parameters,such as spatial matching coefficient,polarizational matching coefficient,and the maximum SINR.Then under condition of one interference source,effect of array mutual coupling on filtering performance of polarization sensitive array is analyzed.