Abstract: Expanding solvent - steam assisted gravity drainage (ES-SAGD) is a new technology that hydrocarbon solvent is co-injected with steam to improve the performance of the gravity-dominated process. Based on the latest researches of ES-SAGD in China and abroad, the concept of this technology is described and its advantages and limitations are evaluated in this paper. Its prospects are also predicted. Moreover, considering the technical researches and practical demands , the direction of ES-SAGD development in China is presented.