The market economy is based on the enterprises of different types of ownership. The state ownership alone can hardly foster the micro-subject of the market economy，and also it cannot inspire the enterprises in the competition，the diverse strategy and the spontaneous mobilization ability of the resources. Therefore，the market and the market economy is diversity. The development of the enterprises in China during the past 60 years，especially during the 30years after the reforming and opening up，has revealed that it is the right way from single to diverse. And in fact，it is the essential of the modern economics.