Among the top chemical manufacturing companies, several have production bases in China:

1. BASF: BASF has a significant presence in China with main production sites located in Shanghai, Nanjing, and Chongqing. The company's Shanghai Innovation Park serves as a hub for research and development in the Asia-Pacific region.

2. Sinopec: As a Chinese chemical manufacturing companies, Sinopec has numerous production bases throughout China. It is deeply integrated into the country's chemical and petroleum industries.

3. Dow: Dow has multiple production facilities in China, including sites in Zhangjiagang, Ningbo, Zhongshan, Nanjing, and Qingdao. The company has been actively expanding its manufacturing capabilities in the country.

4. Shin-Etsu Chemical: Shin-Etsu has established a production and sales network in China, with locations in Zhejiang and Shanghai. The company focuses on the organic silicon sector and has a strong market presence in the region.

These chemical manufacturing companies have invested heavily in China, recognizing the country's importance as a manufacturing hub and a key market for chemical products. Their production bases in China allow them to serve local customers more effectively and contribute to the global supply chain.