A layout structure of flexible circuit board includes a flexible substrate, a chip and a circuit layer. A chip mounting area and a circuit area are defined on a top surface of the flexible substrate. The chip is mounted on the chip mounting area, a space exists between a first bump and a second bump of the chip, and there are no additional bumps between the first and second bumps. A first inner lead, a second inner lead, a first dummy lead and a second dummy lead of the circuit layer are located on the chip mounting area. The first and second inner leads are electrically connected to the first and second bumps respectively. The first dummy lead is connected to the first inner lead and adjacent to the first bump, and the second dummy lead is connected to the second inner lead and adjacent to the second bump.