A flexible display device and a method of driving a flexible display device are provided. The method of driving the flexible display device includes detecting a capacitance change with respect to at least some coordinates of a display area, determining whether bending is occurring through the detected capacitance change, and setting a driving mode in response to a result of the step of determining whether bending is occurring, wherein the driving mode is converted into a bending mode when it is determined that bending is occurring, and the driving mode is set into a force touch mode when it is determined that bending is not occurring.