Graphene has shown promising perspectives in optical active components due to the large active-control of its permittivity-function. This paper systematically reviews the recent developments of graphene-based optical modulators, including material property, single-layer, multi-layer, few-layer graphene-based modulator and corresponding figure-of-merits. The results showed graphene is an excellent material for enhancing silicon’s weak modulation capability after it is integrated into the silicon platform, showing significant influence on optical interconnects in future integrated optoelectronic circuits.