The concept of "natural resources index" was introduced for the first time. According to this index, the industries of the national economy are arranged in an orderly manner. The results of the arrangement reveal the internal relations between industries, which will provide a powerful and feasible tool for the government's various forecasts and decisions. (Introduction: A New Theory of Economics) 1990, the United Nations classified various industries of the national economy, and the Soviet Union, the United States and China also made similar classifications. Although the national conditions are different, the classification is roughly the same. After years of careful investigation, we found that the classification of industries depends on one thing to varying degrees, thus affecting the development of various industries. This kind of thing is natural resources. For the convenience of application, we introduced the "natural resource index", which is denoted as n (a), 0.