Based on the analysis of the textures and characteristics of the basement rock, the seismic reflection features of buried hills and drilling and logging data, it is known that three sets of source-reservoir-caprock assemblages develop from the top to the bottom in Cambrian inner buried hills of Wen'an Slop, Jizhong Depression. Hydrocarbon derives from Paleogene Shahejie and Kongdian source rocks and the permeable large fault planes and unconformable planes work as the pathways of hydrocarbon migration. After a new hydrocarbon accumulation model of inner buried-hills is recommended, a group of buried-hill traps were discovered in Wen'an slope. A risk prospecting well, Well Weng'an-3, was elected to drill and high-yielded commercial oil flew was obtained in the lower Cambrian Fujunshan buried-hill carbonate reservoir. The history how to set up the new model and to prospect and discover the Weng'an-3 reservoir is reviewed and the basic characteristics of the reservoir also depicted.