Northwest China's Xinjiang Uyghur Autonomous Region has long been an inseparable part of the Chinese territory, a white paper said Sunday.

From the Han Dynasty (206 BC - AD 220) to the middle and late Qing Dynasty (1644-1911), the vast areas both north and south of the Tianshan Mountains in Xinjiang were called the Western Regions. Xinjiang was formally included in Chinese territory in the Han Dynasty, according to the white paper titled "Historical Matters Concerning Xinjiang," which was released by the State Council Information Office.

Later dynasties in the Central Plains, some strong, some weak, kept closer or looser contact with the Western Regions, and the central authorities exercised tighter or slacker administration over Xinjiang, it said.

"But all of these dynasties regarded the Western Regions as part of Chinese territory and exercised the right of jurisdiction over Xinjiang," it said.

Through the long formative process of turning China into a unified multiethnic country, many ethnic groups worked together to develop its vast territories and build the diverse Chinese nation, the white paper said.

The unification of multiethnic China was a result of common efforts made by the whole Chinese nation, including the ethnic groups in Xinjiang, it said.