The Tibetan issue was a domestic affair of China, said Hua Chunying, foreign ministry spokeswoman, arguing that no foreign country has the right to interfere.
Her reaction came in response to the scheduled meeting between Obama and the Tibetan spiritual leader Friday in the White House.
Obama has met the Dalai Lama, a Nobel Peace Prize laureate, twice before in February 2010 and July 2011.
The Dalai Lama, a political figure in exile, would undertake anti-China separatist activities in the name of religion, said the spokeswoman.
The meeting would be an unjustified interference with China's domestic affairs and a "serious violation" of the principles of international relations and "cause great damage to bilateral relations", she said.
She said that Tibet has scored brilliant achievements in its economic and social development since its liberation.
"These are facts that won't be denied by anyone without political bias," Hua said.
China firmly opposed any foreign leader meeting with the exiled Tibetan spiritual leader, she said, adding that any country that insists on damaging China's interests would eventually harm its own interests.