Abstract: Characteristics and stages of evolution of soluble organic matter are discussed in the light of its group composition, chromatogram and infrared spectrum. The formation under review is 6,000 meters thick, accumulated with a rate of sedimentation as high as 0.5mm/year. The bottom hole temperature of the test well is 198℃. Geochemical data available indicate that the organic matter contained in sediments has undergone a fairly complete biochemical and thermal-chemical process of evolution—from the burial of organic deaosits, through immature. mature to highly mature stage of condensates and wet gas, having thus established a direct genetic relationship between organic deposits and oil oecurrence. It is estimated from the data of the well that it takes only 6.5 millions for the organic matter to get matured for oil to occur at the depth of 3,300 meters and the temperature at 126℃. At 5,000 meters with temperature over 172℃ sets in the stage of condensates and wet gas generation The facts disclosed in the study is significant in that they add to the wealth of our knowledge about the subject and provide geochemical criteria for identifying the different stages of conversion of organic matter into hydrocarbons.