This paper reviews studies of Tang and Song blue-andwhite porcelains, both archaeologically and scientifically, based on published data, and compares blue-andwhite with sancai, which represents the earliest use of cobalt pigment in Chinese ceramics. Thirty-nine Tang blue-and-white wares and seven Song wares have been excavated from city sites, kilns, a tomb, a shipwreck, and pagodas. These findings identify Tang blue-andwhite as export ware related to the Maritime Silk Road or suggest it was produced for international merchants and visitors in China for daily use or personal collection. Also, the results reflected the connection with Buddhist culture. All Tang and Song blue-and-white are vessels and the motifs on them are plants, insects, a child, geometric and combination patterns. Palmette and lozenge motifs show the influence of Middle Eastern taste. Additionally, we reanalyse and discuss the previous scientific evidence of Tang and Song blueand-white, including body, glaze, and cobalt pigment to reveal the origin of materials and technology of Tang blue-and-white porcelain. The raw pigment of Tang blue-and-white was possibly inherited from sancai, probably from the Middle East, and the biscuit body and high-fired clear lime glaze were provided by white porcelain. Song blue-and-white may utilise native cobalt ore, which possibly was from Zhejiang.K E Y W O R D S blue-and-white porcelain, cobalt pigment, Tang sancai, the Maritime Silk Road, the Middle East