A damage process called fretting fatigue frequently occurs when two surfaces are clamped together under a normal load with a small-scale oscillatory motion due to cyclic loading. In contrast to the constant contact loading, less attention has been paid to variable contact loading which is going to be technically reviewed in this work. Emphasis is put on the efforts made over the past decade and the future challenges such as nonlinear effects of contact loads, friction, frequency, slip amplitude and tribo-oxidation wear will be discussed.