Abstract: Although abnormal high pressure is widely developed in the center and the south of Junggar basin, theforming mechanisms are different due to the discrepancies in sedimentation and tectonics. In the central part, diagenesis and hydrocarbon generation are the key controlling factors. Correspondingly, the main influence elements in the south are under compaction and tectonic uplift. In addition,regional structure controls the distribution of temperature,but lithology, volcanic activity, rifting and suchlike only have important effect on local distribution of temperature. According to the analysis of pressure and temperature fields, it was shown that anomalous temperature and pressure restrain the thermal evolution of organic matters and control the forming and distribution of hydrocarbon.

Key words: Junggar basin, abnormal pressure, pressure coefficient, temperature distribution, reservoir formation