储层原始含油饱和度是评价储层的重要指标 ,它的计算方法有 :岩心直接测定方法、间接确定法和毛管压力曲线计算方法。简要地讨论了这几种方法 ,重点探讨了利用毛管压力曲线计算储层原始含油饱和度的方法 ,针对该方法目前使用中存在的问题进行了改进 ,并在该方法的理论基础上 ,结合新疆塔里木盆地北部的实例 ,提出一种便于利用毛管压力曲线计算储层原始含油饱和度的适用方法 The original oil saturation of reservoir is an important index for reservoir evaluation. Its calculation method includes direct determination of core, indirect determination and capillary pressure curve calculation. These methods are briefly discussed. The method of calculating the original oil saturation of the reservoir by using the capillary pressure curve is mainly discussed. The problems existing in the current use of the method are improved. On the basis of this method, An example from the northern part of Tarim Basin shows a suitable method for calculating the original oil saturation of a reservoir by using capillary pressure curves