Abstract: Aimed at solving the commonly-existent problem that the ore-forming scale is not in proportion to the area of regional geochemical anomaly, this paper puts forward a new concept of “the concentration ratio of regional geochemical anomaly”, describes its definition, related elements and method of calculation. Its main features and adaptability conditions as well as the relationship between the value and scale of the concentration ratio of regional geochemical anomaly and the mineralization size are also discussed. It is held that the concentration ratio of regional geochemical anomaly is a mirror of the concentration ratio of regional ore-forming materials. With this new concept, we can find large-size ore deposits by looking for regional geochemical anomalies. This paper advances a new concept of the intensity of regional ore-forming geological essential factors, and investigates the relationship between the concentration ratio of regional geochemical anomaly and the intensity of regional mineralization geological essential factors.