The Chinese Academy of Sciences topped the Nature Index 2021 Annual Tables, which highlights the institutions and countries that dominate high-quality research in the natural science sector. Harvard University took the second spot, followed by Max Planck Society in Germany and French National Centre for Scientific Research.

By tracking the affiliations of academic achievements from Jan 1 to Dec 31, 2020, Nature Index tables evaluated an institution's or country's share of articles published in the 82 prestigious scientific journals selected by an independent panel of experts, covering life sciences, physical sciences, chemistry, and Earth and environmental sciences, according to its official website.

The Chinese Academy of Sciences has been crowned for nine consecutive years, and continued to hold a seemingly unassailable lead in share in 2020, more than twice that of its nearest competitor, Harvard University.

The Max Planck Society, French National Centre for Scientific Research and Stanford University, continued to round out the top five.

Five other Chinese universities also found place in the top 20, including the University of Science and Technology of China at No 11, Peking University at No 12, the University of Chinese Academy of Sciences at the 13th spot, Nanjing University at 14th, and Tsinghua University taking the 18th spot.

In terms of country ranking, the US generated most of academic output last year, followed by China, Germany, the UK and Japan.

David Swinbanks, the founder of the Nature Index, said the Annual Tables results showed resilience in the research sector during a difficult year stricken by the pandemic, with many institutions either maintaining or advancing their natural sciences output, the official website wrote.

He also said a surge in COVID-19-related articles published more rapidly than usual may partly explain the resilience in publication numbers.