Abstract: Describes the use of stochastic modeling techniques to calculate oil and gas reserves in the concepts,principles and method steps,the technology uses three-dimensional geological model parameters reserves calculation,not only solved the traditional volumetric method when calculating reserves is difficult to get accurate parameters problems,and to more accurately reflect the distribution range of reserves.The results are an example Qiudong gas reserves calculation shows that the use of reserves in the technical computing objective,reasonable,true and reliable calculations can provide geological evidence for oilfield development.