Imports of illegally felled timber into China is destroying some of the world's forests, according to Forest Trends.
Imported timber is used to make furniture for exports
Western consumers also play a major role, the Washington based non-profit group says.
China is importing raw wood to turn it into cheap furniture, plywood and other processed products, 70% of which it exports to rich country markets.
The report says this leads to depletion of the world's forests with devastating social and environmental consequences.
In recent years, the study says, China has emerged as the leading importer of tropical trees.
The problem is that much of this wood is illegally sourced and may come from rain forests and other enviromentally sensitive areas.
The numbers are huge.
The study says exports of wood based products going from China to Europe and the US have gone up 900% in just eight years.
The findings are the result of five years of collaborative research by organsiations in the US, Indonesia and China itself.
Other factors cited include a big increase in demand for wood products in China itself, and China's decision to impose a logging ban to protect its own forests.
That's led to more imports of illegal wood from elsewhere.
An offshoot of the Chinese Academy of Sciences in Beijing contributed to the report