Taiwan announced on Friday it would hold two referendum on bidding to join the world body at the same time as presidential elections next month.
China said the decision to hold one of the referendum on whether to bid for membership under the name "Taiwan" was a move towards formal independence by the island, the official Xinhua news agency said.
China regards Taiwan as a province awaiting reunification, by force if necessary. China and Taiwan split at the end of a civil war in 1949.
A China government statement said the referendum was "Taiwan independence" in a disguised form, Xinhua reported.
"Once this scheme is realised, it certainly will seriously impact relations across the Taiwan Straits, seriously harm the fundamental interests of compatriots on both sides and seriously imperil peace in the Taiwan Straits and even peace in the Asia-Pacific region," Xinhua said, citing the statement.
It was not clear if "once this scheme is realised" referred to the referendum taking place or if it was approved by a majority of Taiwan voters.
The Chinese view this as a dangerous vote. Lord knows what they'd be doing if they weren't on a charm offensive prior to the Olympic games.
Yet once the votes are set, it seems to me that there is danger for Taiwan in voting in favor of the "Taiwan" question or voting against it.
Clearly, however, the mere fact that Taiwanese vote is dangerous for China. The longer this voting stuff goes on, the more that Chinese rulers may worry about democracy infecting China itself.
This is indeed dangerous all around.