High pressure phase relation of the system Fe2SiO4-Fe3O4 was investigated by synthesis experiments using multi-anvil high pressure apparatus. A complete solid solution with spinel structure along Fe2SiO4-Fe3O4 join occurs above 9 GPa at 1200℃. Lattice constants of the solid solution show almost linear variation with composition. A spinelloid phase is stable for intermediate compositions in the pressure range from 3 to 9 GPa. The synthesized spinelloid phase is successfully indexed assuming nickel aluminosilicate V type structure.