This paper presents a novel design of low-cost broad-band dual-polarized microstrip arrays. The antenna uses the slot-coupled feed for one polarization, while the microstrip line feed with slotted ground plane is used for the other polarization. It can make good use of the space on both sides of the ground plane, as the feed circuits for two orthogonal polarizations are placed on each side of the ground plane, respectively. The prototype four-element array designed at C band yields a bandwidth of more than 14% at both ports, and isolation below -30 dB. Good broadside radiation patterns are observed, and the cross-polar levels are below -20 dB at both E- and H-planes.