The formation conditions of phenakite were studied through investigating its gas-liquid inclusions by means of Laser Raman spectrum analysis and microscopic heating/cooling stage. The observation of phenakite samples revealed numerous randomly-distributed yellow acicular transparent solid inclusions, a few red granular opaque solid inclusions, lots of gas-liquid inclusions and healed cracks. The gas-liquid inclusions in phenakite were divided into two types according to their forms and substances. Type Ⅰ included rich liquid two-phase H₂O-NaCl inclusions (Ⅰa) and pure liquid H₂O-NaCl inclusions (Ⅰb), whereas Type Ⅱ could be further divided into three-phase H₂O-NaCl-CO₂ inclusions containing liquid CO₂(Ⅱa) and two-phase H₂O-NaCl-CO₂ inclusions without liquid CO₂(Ⅱb). Then some gas-liquid inclusions of different types with clear demarcated gas part and liquid part were chosen to do further test. Using Laser Raman spectrum analysis, the authors affirmed that phenakite is a kind of silicate which contains Be as the matrix for inclusions, and that the gas part of the gas-liquid inclusions contain such components as CO₂ and water vapor, whereas the liquid part is NaCl aqueous solution with the dissolution of a little CO₂. Two different gas-liquid inclusions were chosen for microscopic heating/cooling stage test, and the results show that the homogenization temperatures of the inclusions are from 378.9℃ to 425.5℃ by homogenization method, and their freezing points are about -12.1～-6.3℃ by freezing method. These data were used to figure out the salinities of these inclusions, which are 9.60%～16.14%. Calculations show that the homogenization pressures range from 234.44 MPa to 428.56 MPa. The formation temperature and the formation pressure of phenakite estimated from homogenization temperature and homogenization pressure are about 378.9～425.5℃ and 234.44～428.56 MPa respectively.