Abstract: A source driving device and a driving method for a display panel of a liquid crystal display are provided. The source driving device comprises a source driver and a current regulator. The source driver receives image data and then outputs image data via a plurality of source lines to drive the display panel. The current regulator is electrically connected to the source driver. By evaluating the image data received by the source driver, when the voltage difference between any two adjacent source lines caused by the image data is larger than a predetermined value, the current regulator is activated to adjust the driving current on the source lines, such as reducing the driving current, to prevent the block dim phenomenon.