The invention provides a Schottky diode structure. An exemplary embodiment of a Schottky diode structure includes a semiconductor substrate having an active region. A first well region having a first conductive type is formed in the active region. A first doped region having the first conductive type is formed on the first well region. A first electrode is disposed on the active region, covering the first doped region. A second electrode is disposed on the active region, contacting to the first well region. A gate structure is disposed on the first well region. A second doped region, having a second conductive type opposite to the first conductive type, and is formed on the first well region. The gate structure and the second doped region are disposed between the first and second electrodes.