Abstract: The hair and serum of 89 normal children and. 80 developmentally retarded children were collected, and the content of zinc, copper, iron, manganese and chromium were determined by atomic absorption spectropho-tometry. It was fund that, while content of copper in developmentally: retarded children was higher than that in normal children, and the content of zinc, manganese and chromium in developmentally retarded children were lower than normal children. The fact provides an important clue for further study of pathogenesis of this disease. We have made and initial exploration in the cause of the changing occurred in trace element in hair and serum of developmentally retarded children and its clinical significance.

Key words: zinc, copperi, ron, manganese, chromium, hair, serum, trace etement, developmentally retarded children