A radioisotope induced X‐ray fluorescence method was used to measure trace elements in Ming porcelain. Thirty pieces of blue‐and‐white Chinese porcelain, belonging to the Ch'eng Hua reign (AD 1465‐87) and rescued from a shipwreck, were analysed along with two fake reproductions. The measurement system consisted of an Si(Li) detector, a109Cd annular source and a personal computer with a non‐linear fitting least‐square program. The relative intensity ratios of manganese, cobalt, rubidium, strontium, zirconium, and niobium were determined. Rb/Sr and Mn/Co ratios between two to five and two to four respectively correspond to antiqu