The Asian Development Bank (ADB) said in Beijing on Wednesday that China's economic growth would moderate to 10 percent this year and 9.8 percent in 2009.
China's economic growth hit 11.4 percent in 2007 - the highest in 13 years.
The ADB also warned that rising food prices would stoke inflation pressure in the economy in its annual outlook report released on Wednesday.
It said the country's inflation rate was expected to hit 5.5 percent in 2008 and remain at around 5 percent in 2009, up from 4.8 percent in 2007.
Previously, ADB put its forecast for China's GDP growth in 2008at 10.8 percent in September last year, while the inflation rate was predicted at under 4 percent, at about 3.8 percent, for the year.
The Manila-based bank also said China's export growth may slow to 19 percent this year, down from 26 percent in 2007, in the face of weakening global demand.
ADB's report came a day after the World Bank revised its 2008 China growth forecast to a lower 9.4 percent, warning the country of rising inflation and weaker exports.
The Chinese government said in March it aimed to maintain the country's economic growth at eight percent this year, while the inflation target was fixed at 4.8 percent.