1. The trend of global economic integration. Globalization, as the product of highly developed production socialization and division of labor, is the inevitable trend of world economic development. The factors of production flow freely around the world, and finally realize the optimal allocation of global resources. The Yangtze River Delta region has become a strategic region for China to attract multinational companies' investment in recent years because of its superior location conditions, strong industrial supporting capacity, high-quality labor resources, relatively strong comprehensive scientific and technological strength and good investment environment. According to this general trend, the Yangtze River Delta will continue to accept international industrial transfer and become the sixth largest urban agglomeration in the world.

2. The trend of regional economic integration. "Regional economic integration" refers to the economic alliance formed according to the internal relations between natural regional economy, commodity flow, national cultural traditions and social development needs. Globalization is an inevitable trend, and regional economic integration is the only way to connect with globalization. From the perspective of its own development needs, it is an objective choice for all parties in the Yangtze River Delta region to realize economic integration by building a modern metropolitan area. Regional economic integration is the only way for Shanghai to build an international metropolis and the only choice for Jiangsu and Zhejiang to integrate into globalization.

(B) the strategic significance of regional economic development in the Yangtze River Delta to China.

The strategic significance of regional economic development in the Yangtze River Delta to China is reflected in three aspects: First, the sustained and healthy economic development in this region will certainly have a demonstration effect on other parts of China and a positive impact on national modernization; Second, in the process of implementing the regional economic development strategy, the change of regional internal structure, the improvement of functions and the overall integration will generate new energy, making this region gradually become a new economic highland, which will have a strong driving effect on other regions of China, especially the economic belt along the Yangtze River; Third, the rapid economic development in this region will change the economic structure of East Asia, improve China's position in the world economic system, and play a significant role in supporting China's participation in international competition.