Abstract: The transportation of deepwater oil and gas resources will be threatened seriously once pipelines are plugged by hydrate. Therefore, it is essential to predict quantitatively the formation of hydrate in different working conditions. At present, however, the formation kinetics mechanisms of gas hydrate are not clear. In this paper, the domestic and foreign research progress on formation kinetics of hydrate in water-in-oil systems was illustrated systematically, the kinetics model used for nucleation and growth of gas hydrate in the oil-gas-water multiphase systems with oil as the dominant phase was mainly introduced. Then, the advantages and disadvantages of main models were analyzed. Finally, based on the status of researches on formation kinetics of gas hydrate in water-in-oil emulsion systems, it was recommended to study the formation of hydrate in multiphase systems with the coupling mechanism of mass transfer and intrinsic reaction as the beginning point. And then combined with the test studies of different scales, a more applicable model for the formation of hydrate will be established by taking into consideration the physical process, mass transfer and heat transfer restriction in multiphase systems, so as to provide the assurance for the flow safety of pipelines.