Abstract: Suberinite occurs commonly in Jurassic coals of Xinjiang, which is formed from suberized cell walls, particularly in plant periderm. The proportions of suberinite in organic macerals are generally less than 2% if only suberized cell walls are counted, and maximize about 20% if both suberized cell walls and corpocollinite which are contained within the cork cells are couned, In vitrinite reflectance range of 0.35%~0.70% R., severe optical changes of suberinite are demonstrated, but its changes in morphography and content are insignificant. Those phenomena reflected that the suberin and wax fractions in suberized cell walls were obviously lossed in this stage, and the lignified cellulose and cellulose fractions as skeleton of cell walls were demonstrated indistinct changes. Suberinite are progressively evolved to telinite or telocollinite in optical properties during thermal maturation, upon to 0.90% VR。, suberinites were impossibly to be identified.