He is professor emeritus at the Department of Mathematics, Vanderbilt University in the United States.
In September 1957, he was sent to Moscow State University in the USSR, where he conducted one and a half years of research with the prominent mathematician I.M.
During the 1983-1984 academic year, Xia served as a visiting member at the Institute for Advanced Study in Princeton.
His son, Jingbo Xia, is a professor of mathematics at SUNY Buffalo.
His son-in-law, Bennett Chow, is a professor of mathematics at UC San Diego.