A chip on film (COF) structure for a liquid crystal panel is disclosed, and comprises a flexible substrate, an output edge, a first wire bonding portion, two second wire bonding portions, a fan-out trace portion, and two array trace portions. A long direction of lead strips of the second wire bonding portion is parallel to the output edge, and the array trace portions connect one end of the lead strips of the second wire bonding portion to the output edge. The design of the second wire bonding portions parallel to the output edge and turning traces of the array trace portions can lower the length of the fan-out trace portion, so that it is advantageous in a design trend of narrow frame edge of a liquid crystal panel.