Abstract: Since the 1970’s,there have appeared a lot of views about the source of ore substances in the Shilu deposits on Hainan Island.Since 1983,the author and his colleagues have found two layers of volcanic turfs in Bed No.6 that is the main ore-bearing bed in the Shilu Group,and found volcanic tuff layers at a few localities in the upper part of the schist of Bed No.5 at the base of the principal ore bed,A unit of low-grade volcanic-sedimentary clastic rocks with lenticular volcanic lavas and volcanic tuff has been tentatively defined in the middle-upper parts of Bed No.5.They discovered diopside rocks in the cross section of volcanic rocks and not devitrified volcanic glass in altered diopside dolomite.Therefore it is proposed that the ore substances of the Shilu iron deposit might originate mainly from submarine proximal volcanic eruption.