The study, published by the U.S. Pew Environment Group, showed that the Chinese invested $54.4 billion in the technology in 2010, up from $39.1 billion in 2009, the BBC reported Tuesday.
While investment by the United States increased by 51 percent to $34 billion, America nevertheless slipped from second to third in the ranking, behind Germany's $41.2 billion, the study said.
Around the world, the low-carbon energy sector -- which does not include nuclear power -- attracted $243 billion of investment, a 30 percent increase from 2009 and a significant 630 percent rise since 2004.
The report examined the clean energy sector's investment and technological trends in the Group of 20 leading economies.
In addition to attracting the most investment, China was also the world's leading producer of wind turbines and solar energy units, and overtook the United States in 2009 as the nation with the most installed clean energy capacity, the report said.