In this paper,30 elements in ambient PM_(2.5) in Nanjing were collected by Teflon filter,digested by microwave and nitric acid-hydrogen peroxide-hydrofluoric acid,determined by ICP-MS. Some measurement parameters were obtained from method study. The elements had good linearity range in 0 μg/L ~ 500 μg/L. Of all the elements,the MDL were 0. 02 ng/m~3~ 15 ng/m~3,the RSD were 0. 5% ~ 19. 6%( n = 6) and the recoveries ranged in 78. 5% ~ 126%. Results from practical sample showed that the annual mean concentrati...