Abstract: Since the discovery of the Dajingtou volcanic rock in Pingyi County, the problem of its lithology and the ore-bearing potentiality of diamond has not been solved. Recently, two boreholes unveiled fresh spotted rocks at the depth of 580m or so, and three diamonds were selected from them. According to the rock features, lithogeochemistry and heavy mineral characteristics, it is considered that the Dajingtou volcanic rock is lamproite-bearing diamond, which might have caused the anomalies of diamonds and heavy minerals in the lower reaches of the tube. Combined with a number of suspected lamprophyre exposed in surrounding areas, it is considered that there is a great potential for primary diamond ore.