A COA (Color filter On Array) substrate and a manufacturing method using the same are disclosed. The method includes: forming a first metal layer, a gate insulation layer, a color resist layer, an active layer, a second metal layer, a passivation layer, a via hole, and a transparent conductive layer in order. The via hole is used for connecting to the transparent conductive layer with the second metal layer. The transparent conductive layer is formed on the passivation layer. A gate electrode is formed by pattering the first metal layer. A drain electrode and a source electrode are formed by pattering the second metal layer. In the present invention, the color resist layer is made before the second metal layer.