Metamaterials (MMs) composed of periodic resonant subwavelength structures exhibit exotic electromagnetic properties that do not exist in nature, and open an avenue for electromagnetic waves (EMWs) manipulation. Dispersion is an inherent property of MMs. By engineering the electromagnetic resonances of MMs, extraordinary dispersion can be achieved thereby one can break the traditional physical laws and manipulate the EWMs at will. Subsequently, a serial of applications emerge including super-resolution imaging/lithography, electromagnetic absorber/radiator and planar optical devices. In this review, we summarize several typical approaches, theories and relevant applications of dispersion engineering of MMs.