Abstract: Based on the particular geological conditions of forming biogenetic gas reservoir in Qaidam basin, it is calculated from Monte Carlo method that the total resource amount of biogenetic gas is 14755x10⁸m³, integrated with the results obtained from trap geological analysis and basin modeling method. A lso, petroleum assessment system (PASYS) is adopted to evaluate the resource potential of this basin and plays/blocks, and the favorable areas for biogenetic gas prospecting in the near future are Beipo (northern slope) and the Central Depression with corresponding exploration targets, of which the buried structural trap and non -structural trap are the main concern in Qaidam basin.

Key words: Qaidam basin, biogenetic gas, resource, evaluation, exploration potential