Gas Hydrate is usually formed during the transportation and treatment of oil and gas,resulting in the plugging of gas pipeline and equipment. Three thermodynanic calculation formulas are analyzed to deal with this problem. The lowering of the freezing point of the inhibitors △T is used to calculate the formation temperature of natural gas hydrates. This is. considered to be a good approach because it is not limited by what kind and what concentration of inhibitors one uses. Besides, the rate of lowering of the freezing point could be easily measured. The result of testing methanol and mono-ethylene glycol in a reactor shows that adding 10% inhibitors to the reactor can prevent the hydrates formation.Kinetic inhibitors are favored in the present research. They are divided into two types, polymer and surface-active agents. Their characteristics, mechanisms, and application prospect are separately discussed.Polymer inhibitors exhibit better efficiency. The result of field application of VC-713 inhibiter is also given in this article. In practice, the combination of thermodynamic inhibitors and kinetic inhibitors gives better result.