Phase relation studies for ternary Fe-Ni-S system have been performed by author. Their results are described as mainly phase diagrams. Many diagrams were obtained by integrating after Sugaki et al, and Kitakaze at al., and adds additional new data and new knowledge were obtained by outhouses. Phase relations at 1,100, 1,000, 900, 875, 750, 800, 750, 700, 650, 600, 550, 500 and 450°Cusing the dry method were showing. Further, cross sections for (Fe,Ni)-S and po-hx from 1,000 to 450°C by integrating after Kitakaze et al.