The geochemical investigation in the continental shelf of the East China Sea has been mad at 12 stations. Vertical profiles of the concentration of Mn and Fe in the pore Water of the near shore and off shore sediments are presented, and compared with corresponding profiles of the solid cam-pounds of Mn and Fe in the sediments. A preliminary analysis of the results has been given and according to these data, a rough model of Mn cycle is preliminarily suggested.