China's growth prospects this year are overshadowed by unprecedented uncertainties, since reform dividends aren't likely to materialize quickly, downward pressure persists and the global outlook is unclear, the China Academy of Sciences said in a report released on Thursday.

This assessment from a top national think tank offers a grim outlook, even as economists and other institutions provide positive forecasts. Many global banks have recently raised their forecasts for China in 2014 to reflect accelerated growth.

However, the CAS has forecast that this year's GDP growth rate will slow by 0.1 percentage point from 2013. Official 2013 GDP figures haven't yet been released, but the CAS estimated the growth rate at 7.65 percent.