Prof. Xia Nai (1910--1985) was an outstanding Chinese archaeologist of substantial scholarly achievement. His academic researches featured profound erudition, a wide field of vision and a rigorous scientific approach. In archaeology of prehistoric China, his major contributions consisted in the amendment of the chronological system of Neolithic cultures in the upper Yellow River valley, the standardization of the denomination of cultures in Chinese archaeology, the offering at an earlier time of the theory of pluralism on the development of the Neolithic culture in China, and archaeological inquiry into the origin of Chinese civilization. In archaeology of historic times in China, he was good at further and further researches in the light of abundant archaeological data and reliable literary records. His attainments in the archaeological study of the history of science and technology in China as well as that of Sino-Western communications deserve to be emphasized as pioneer, important contributions.