ZHANG JIAXIANG Zhang Jiaxiang, astronomer, was born in Oct. 1932 in Nanjing, Jiangsu province. He joined the Purple Mountain Observatory, Chinese Academy of Sciences in 1951 as a technician, supervised by director Zhang Yuzhe.  Since then, Prof. Zhang has been working in the observatory successively as an assistant researcher, associate researcher, and senior researcher. In 1957, Zhang Yuzhe and Zhang Jiaxiang worked together and published an important paper discussing the orbit of artificial satellite. This fundamental paper started early age of orbit computation area of artificial satellite in China. From 1965 to 1972, Prof. Zhang led a research group to accomplish the project of orbit determination of the Chinese first artificial satellite and thereafter the systematic studies of the orbit of Chinese synchronous satellite. All the researched results were applied successfully and made important contributions. Since 1960s, Prof. Zhang  has been leading his team to explore the field of research in small bodies. They totally discovered more than 150 internationally numbered new minor planets and 4 new comets. In 1990s, in the wellknown event “Impact of Comet SL9 on Jupiter,” he accurately predicted a series of collision time between 19 comet nuclei and Jupiter, based on his selfestablished numerical model of solar system dynamics. In most recent 10 years, he is named as the chief scientist, leading a  project of “Construction of NearEarth Object Telescope，” which has been successfully completed on the whole. Prof. Zhang published more than 30 papers in his field. he received AllChina Advanced Worker Awards in 1956 and 1959 respectively. He received the second class award of National Natural Science Award in 1987, as well as CAS achievement award many times. To recognize his contribution in his field, HarvardSmithsonian Observatory in Boston, USA, named a new asteroid they discovered “Jiaxiang” in 1991. He was chosen as first term “10 ScienceTechnology Stars” of Nanjing in 1995. In 1999 in Beijing, he attended the award meeting for sciencetechnology specialists who made outstanding contributions to the project of “Two Bombs and One Satellite”  convened by the central authorities.