Copper red glazes made at the pottery center of Jingdezhen during the Ming and Qing dynasties are one othe the most fameous and precious porcelain products of China. They were based on earlier technology developed in the Tong-guan kiln in Tang dynasty and on the Ru and Jun wares of the Song dynasty. The earliest copper red glazes appeared as early as the late Yuan dynasty. The dazzlingly beautiful altar red and ruby red products were created at Jingdezhen in the Yongle and Xuande periods of the Ming dynasty. Other copper reds created at Jingdezhen were the Longyao red of the Kangxi period and the imitation Jun, flambe and others of Yongzhen and Qianlong periods of the Qing dynasty. Chinese copper red glazes have been held in high regard throughout the world, and many have wondered at their complex and sophisticated technology. Through analysis, we unlock some of the technical secrets of these famous wares in order that more people may appreciate the technical excellence underlying the visual appearances of these wares and that these glazes may be replicated better by contemporary ceramic factories in Jingdezhen. Seven examples of Jingdezhen copper red glazes were analyzed by scanning electron microscopy, x-ray diffraction, refiring tests and microprobe analysis to determine the compositions, microstructures and firing temperatures.