A power grid of an integrated circuit (IC) is provided. The power grid includes a plurality of first power lines formed in a first metal layer, a plurality of second power lines formed in the first metal layer, a plurality of third power lines formed in a second metal layer and a plurality of fourth power lines formed in the second metal layer. The second power lines are parallel to the first power lines, and the first and second power lines are interlaced in the first metal layer. The third power lines are perpendicular to the first power lines. The fourth power lines are parallel to the third power lines, and the third and fourth power lines are interlaced in the second metal layer. A first power pitch between two adjacent third power lines is greater than a second power pitch between two adjacent fourth power lines.