Since China's reform and opening up to the outside world, following the development of the commodity economy and the transformation from the planned economy system to the socialist market economy system, there has taken place a change of important significance in the operational guiding ideology of the departments responsible for various trades of the mineral industry, i.e. a change from a unitary economy to a diversified economy. These departments have implemented the principle of developing a diversified economy with one industry taken as the main line of business activity and attaching equal importance to both mineral and non-mineral industries, and made enegentic efforts to develop a diversified economy, including the tertiary industry. As a result, they have made remarkable achievements not only in the great increase in income but also in the absorption of a large number of redundant employees that flowed out from the principal line of business, thus making important contributions to optimizing the industrial structure, stabilizing the ranks of employees and promoting the development of the mineral industry.

In the recent several years the department in charge of the coal industry has practised a principle of "taking coal mining as the foundation, developing a diversified economy and ensuring a comprehensive development", optimized the industrial structure, broken up the pattern of a unitary industry, a simple variety and a single-product business operation and made great efforts to improve the quality and performance of the economic growth of the non-coal industries. As a result, the total value of production and marketing of the various non-coal business activities of the whole industry  in 1996 reached 48.59 billion yuan, equivalent to 31.31% of the total output value of the coal industry of the whole country and 54.7% of the total production value of China's State-owned key coal mines. In the meanwhile, in the period of 1993~1997 the State-owned key coal mines cut down and found other positions for a total of 1.14 million redundant employees, including 0.51 million people for net reduction and 0.37 million people for placement in other job positions, thus making an important progress in reducing staff and improving efficiency.

While intensifying its oil-gas exploration activities, the Chinese National Petroleum   Corporation has practised a strategy for developing a diversified economy and formed preliminarily a new framework of industrialized, scaled and grouped diversified business activities. In 1997, the Corporation had a contigent of up to 400,000 employees engaged in diversified business activities, which made sales of 29.88 billion yuan, making up 17.8% of the corporation's total sales of 167.83 billion yuan, achieved a profit and tax total of 1.91 billion yuan, created an enterprise's increment of 6.82 billion yuan and produced over 200,000 tons of grain, 61,000 tons of vegetables and 77,000 tons of meat, eggs and aquatic products. These business activities have thus gradually become a new area of economic growth of the Corporation.

It was proposed as early as in 1985 for the geological exploration sector to exercise the principle of taking the development of geological markets as the breakthrough point, centering on geological survey and mineral prospecting and developing a diversified economy with one line of business retained in the dominant position. In 1996, over 250,000 employees of the trade were engaged in diversified business activities of other industries, which brought about an annual total revenue of 12.875 billion yuan. These activities not only helped find jobs for redundant employees but also gained a profit of 41.37 million yuan, thus playing a positive role in promoting the stabilization of the contigent of the staff and workers for the development of the geological exploration undertakings.