The Giant magnetostrictive materials（GMM） have some distinct advantages such as large magnetostrictive coefficient,fast dynamic response,and high electromechanical conversion efficiency,which can be used into power conversion among electric,magnetic,mechanics and heat,etc. Based on multi- field coupling theory,a brief description about the characteristics of GMM is given,comparing with the piezoelectric ceramic material,and the relationships between these characteristics and magnetic field intensity,temperature,frequency is stated. Then,various mathematical models with different features are stressed,along with the multi- field coupling effect. Meanwhile,the foreign and domestic researches and applications of GMM are introduced,including the operation principle,structure and basic performance of GMM devices. Finally,the development of GMM in the future is discussed.