A liquid crystal display and a method for driving the same, which improve image quality by increasing data line charge speed, are provided. In the display, a preparatory charging controller receives current image data to be provided to m current pixels of an nth horizontal line and a current vertical polarity-reversal control signal for vertically controlling polarities of the current image data, compares current image data with previous data provided to m corresponding previous pixels of an n−1th horizontal line, compares the current control signal with a previous one, and determines a logic value of a preparatory charging control signal based on the comparison. A data driver performs either a first operation for connecting and separating m data lines connected respectively to m current pixels, or a second operation for maintaining the m data lines separated, according to the logic value and provides the current data to the m pixels.