A driving apparatus and method for active matrix organic light emitting display includes a writing element, an auto-zero element, a driving element, a switching element and a storage element. The invention employs an auto-zero mechanism to compensate threshold voltage variations of each driving element to improve image uniformity. Data loading is accomplished by charging the storage element with a current. Loading voltage may be modulated by controlling the amount of current and by controlling charging time. The invention saves a capacitor than conventional techniques, and can increase the aperture ratio of pixels and reduce the complexity of driving method.