BEIJING -- Beijing has once again become the top science city globally, followed by New York, Boston, the San Francisco-San Hose region, and Shanghai, according to the Nature Index global science city 2020 rankings, released on Saturday at the ongoing 2020 Zhongguancun Forum.

Besides Beijing and Shanghai, four other Chinese cities - Nanjing, Wuhan, Guangzhou, and Hefei - ranked among the top 20 global science cities, as measured by the Nature Index, which tracked the authorship of articles in 82 high-quality research journals.

David Swinbanks, the founder of the Nature Index, said the concentration of talent, funding, research institutions, and other resources is crucial for the top five global science cities to maintain their leading positions.

As China's sci-tech innovation hub, Beijing has formed a close collaboration network of scientific research with other Chinese and foreign cities, Swinbanks added.