China’s slowdown appears to have bigger repercussions for other countries than had been expected, the IMF said.
The troubles in China have sent the prices of commodities such as oil and copper sliding.
The falls have hit exporters of commodities, such as Brazil and Russia, particularly hard.
The IMF’s warning comes ahead of a meeting of G20 finance ministers and central bankers in Ankara on Friday and Saturday.
The IMF said that the problems could lead to “much weaker outlook” for global growth.
However, the fund still expects the global economy to expand by 3.3% this year, slightly lower than 3.4% in 2014.
The US is forecast to grow by 2.5%, up from 2.4% in 2014, the eurozone should expand by 1.5%, nearly double the 0.8% seen last year, while China should expand by 6.8%, down from 7.4%.
The IMF called on China to keep reforming its economy despite the recent falls in the stock markets on the mainland.