The Kuomintang are exhibiting documents, including the 1842 Treaty of Nanking, to show how they tried to end colonial domination of China _ and advertise their government's claim to be the legitimate ruler of all China.
``The Republic of China on Taiwan's existence is still a fact, though we have had some frustrations,'' said Foreign Minister John Chang, using Taiwan's official name.
The Kuomintang fled the mainland in 1949 after losing a civil war to the communists and protested when Britain opened negotiations with Beijing in 1984 over Hong Kong's return.
They no longer compete with Beijing to represent China internationally, but still officially claim all of China.
Mr Chang said possession of the treaty gave Taiwan sovereignty over Hong Kong.
If Britain had not recognised Beijing in 1950, it would have negotiated Hong Kong's return with the Republic of China's successors in Taiwan who had turned a virtual dictatorship into a vibrant, free-market democracy, Mr Chang said.
``I can tell you if they were negotiating with us then, there wouldn't be any worries'' about maintaining Hong Kong's freedoms and capitalist system, Mr Chang said.
China has promised to leave Hong Kong's systems unchanged for 50 years. But plans to roll back some civil liberties have raised concerns of backsliding._ AP