In this paper, the effects of shapes and orientations of rods on absolute PBGs in 2D square lattice are studied. By replacing round rods with square rods, which sides are along with the direction of elementary lattices vectors, the absolute PBGs in 2Dsquare lattice with wave vector in periodic plane and off periodic plane have been studied and then through changing the square rods orientation, the changing of the width and position of PBG has been obtained.