Abstract:Gold ore prospecting work in No.284 east mining area in Urad Zhongqi in Inner Mongolia has been carried out for many years. However there is no breakthrough. In the former research, it was regarded that ore bodies occurred in fracture altered quartz diorite with small scale. Based on geological data and field work, it is put forward that carbonaceous mylonite is major ore-bearing rock. Through core sampling and analysis of the former construction drilling core, a new gold body is discovered in carbonaceous phyllonite with the scale of 500m(trend)×500m(dip). It provides a powerful support for the new idea. This new gold ore body occurs in ① alteration zone which controlled by F9 fault. The ore body is plunging with the trend of SW. Large ore body can be easily formed in the structures intersection. The metal sulifide content of gold mineralization is low, and the gold can be visable which has a wide range in particle size. According to the new idea, a prospecting breakthrough can be expected at next exploration stage, and more gold reasource will be found. The new idea points out a direction for the mining area and adjacent mining area in the next exploration stage.