I found this reference the other day about the history of interracial relationships in China, and found it quite interesting and insightful, and worthy of posting here.
There have been various periods in the history of China where large numbers of Arabs, Persians and Turks from the Western Regions (Central Asia and West Asia) migrated to China, beginning with the arrival of Islam during the Tang Dynasty in the 7th century.
Due to the majority of these immigrants being male, they often intermarried with local Chinese females. While intermarriage was initially discouraged by the Tang Dynasty, it was later encouraged during the Song Dynasty, which allowed third-generation immigrants with official titles to intermarry with Chinese imperial princesses. Immigration to China increased under the Mongol Empire, when large numbers of West and Central Asians were brought over to help govern Yuan China in the 13th century.
By the 14th century, the total population of Muslims in China had grown to 4 million.  After Mongol rule had been overthrown by the Ming Dynasty in 1368, this led to a violent Chinese backlash against West and Central Asians. In order to contain the violence, the Ming administration instituted a policy where all West and Central Asian males were required to intermarry with native Chinese females, hence assimilating them into the local population. Their descendants are today known as the Hui people.