Abstract: Being developed for more than forty years，Shengtuo area has come into the advanced exploration degree stage．In order to study the size and distribution of the undiscovered reservoirs in Shengtuo area，the reservoir trap size sequence method is applied to evaluate its remaining resource potentia1．The studies show that there are still 124 undiscovered reservoirs whose reserves in every pool are greater than 30×10 4t and the quantities of total remaining resource are about 1.46×10 4t．Not only did the undiscovered reservoirs include small-scale pools of which sizes are smaller than 1O0 ×10 4t，but also 35 large．scale ones of which total reserves are 9672×10 4t．The quantities of the remaining resources and the undiscovered reservoirs of Shengtuo area，forecasted by reservoir size sequence method，can play an important role in finding out the optimum direction of exploration and guiding the future exploration of this area．