An image forming apparatus and method for controlling a charge of a toner are provided. The apparatus and method includes a toner supplying roller; a developing roller for supplying the toner to an organic photoconductor; a charge controller for adjusting the charge of the toner on the developing roller; a developing current detector for detecting a change in current for a developing voltage; and a charge controlling voltage controller for adjusting a charge controlling voltage according to the detection result. The apparatus can uniformly maintain the quality of an image by recognizing a change in the charge of toner based on a change in the environment. Also, the image forming apparatus indicates a proper toner replacement time by determining when the charge of the toner is abnormally low as a toner shortage state and displaying the toner shortage state on a panel operating unit.