Yielding, a fault lateral sealing evaluation method is often used to predict the height of oil column. But the predicted results were found to partially disaccord with the distribution of oil and gas. Indepth study shows that this phenomenon may be attributed to failing to consider the lower limit and seal area of fault lateral sealing. When the minimum SGR at a certain depth range of fault plane is greater than the lower limit of fault lateral sealing, the whole fault is of lateral sealing ability at this depth range. Yielding method can be directly applied in the fault lateral evaluation and prediction results are well coupled with oil and gas distribution. However, when the minimum SGR at a certain depth range of fault plane is less than the lower limit of fault lateral sealing hydrocarbon, the lateral seal ability of faults at this point outside the sealed area may be underestimated or overestimated using Yielding method. In order to predict hydrocarbon column height more accurately, this study focused on improving fault lateral sealing evaluation method of Yielding. With Wenan slope faultingtype trap in the Jizhong Depression as an example, fault trap lateral sealing ability was quantitatively evaluated by the improved method. The results show that prediction results of Sha No1 and No2 traps are in conformity with oil and gas distribution, indicating that the Yielding method is feasible for quantitative evaluation of lateral sealing of a fault. This revises shortcoming of underestimation or overestimation to sealing trap capability using Yielding methodology, thus improving accuracy degree of predicting lateral sealing ability.