The annual Research Fronts report, which tracks the hottest and emerging topics in frontier science, has ranked China No 2 in the world for cutting-edge innovation.

China, second only to the United States, leads the world in 25 of 143 topics in frontier natural and social science, according to the 2017 report released on Thursday.

Frontier science refers to cutting-edge data, hypotheses and models that have not been widely tested or accepted.

The report, now in its fourth year, is compiled by the Chinese Academy of Sciences and Clarivate Analytics, a global analytics firm, and is based on citation analysis of papers published from 2011 to 2016.

Frontier research topics — which are divided into 10 broad categories — reflect global interests and scientific development trends, said Bai Chunli, president of the CAS. Topics can range from nanomaterial assembly and smog formation to superconductors for computers.

"China's scientific development has entered a new era, with emphasis on making breakthroughs in fundamental scientific research," Bai said, adding that the Chinese government may support many of the identified areas over the next decade. "These breakthroughs might change the future pattern of the world."

Six countries — the US, China, Britain, Germany, France and Canada — made the greatest contributions in the 143 research topics, according to the report.

Of the 10 major scientific categories, the US leads in eight categories, ranging from physics to biology. China leads in two: material science and computer engineering.?

China has entered the second tier of global science innovation and research, but there is still a significant gap with the US, the report said.