Marine inorganic photochemistry, as one of the important branches of marine chemistry, is significantly connected with marine biology, marine ecology, marine geochemistry and marine environment, and plays an important role in the development of marine sciences. To date, lots of investigations in the field have been conducted home and abroad. As for the following development of marine inorganic photochemistry, it is greatly of significance to summarize these research works. This paper detailedly summarizes the present research progress in the photochemistry of Fe, Mn and Cu, with an emphasis on investigations on photochemical processes which could affect existing forms of these metal elements in seawater. The problems and shortcomings in the study field are pointed out and some suggestions for the future study are put forward.