BEIJING China expressed dissatisfaction on Wednesday after Japan's de facto embassy in self-ruled Taiwan, which Beijing considers a breakaway province, said it would change its name include the word Taiwan.
Japan, like most countries in the world, maintains only informal relations with Taiwan while it has diplomatic ties with Beijing.
From Jan. 1, the Interchange Association, Japan, will become the Japan-Taiwan Exchange Association, according to a notice on its website.
Chinese Foreign Ministry Spokeswoman Hua Chunying said China had a consistent stance when it came to Taiwan and opposed attempts to create "one China, one Taiwan", or "two Chinas".
"As for the negative move by Japan on the Taiwan issue, we are extremely dissatisfied," Hua told a daily news briefing.
China urges Japan to uphold the "one China" principle, appropriately handle Taiwan-related matters and not send a wrong message to Taiwan and the international community or create new disturbances in China-Japan ties, she added.
An Interchange Association official in Japan said the decision to rename itself was taken to boost recognition.
Defeated Nationalist forces fled to Taiwan in 1949 at the end of a civil war with the Communists. China has never renounced the use of force to bring Taiwan under its control.
China and Japan also have difficult ties. Beijing has repeatedly urged Japan to show greater repentance for World War Two atrocities and the two sides have a festering territorial dispute in the East China Sea.
However, Japan's 1895-1945 rule in Taiwan is seen by some as having been good for the island's development, unlike perceptions of Japan in other parts of Asia, particularly in China and Korea, which are often deeply negative.
(Reporting by Ben Blanchard; Additional reporting by Kiyoshi Takenaka in Tokyo; Editing by Nick Macfie)