Speaking at a news conference on Monday in Beijing, China's Taiwan Affairs Office spokesman, Zhang Minqing, said the speech had done nothing to reduce tensions in the strait.
"If Chen Shui-bian dares to challenge the people of the world, we will safeguard our sovereignty and territorial integrity at any cost."
Zhang also warned the island not to rock the boat ahead of the Olympic Games in Beijing in 2008, stressing that China did not care what Chen said, only what he did.
In his address on 20 May, Chen ruled out any immediate steps towards independence in a move aimed at placating China and key ally the US.
While Washington welcomed his address, Chen appears to have failed miserably with Beijing. The two sides have been foes since the end of the Chinese civil war in 1949.
The US welcomed Chen's speech as "responsible and constructive" for avoiding an immediate showdown with China and added it created an opportunity for the two rivals to resume dialogue.
The last word
But China, which regards Taiwan as a renegade province that must be returned to the fold - by force if necessary - told Washington not to be deceived by the speech.
Zhang said there was no sign that Chen was willing to alter his course towards seeking an independent country.
"He is riding near the edge of the cliff, and there is no sign that he is going to rein in his horse."