SnPbSb4S4Sb2S3 system was investigated by complex physical-chemical analysis methods, and state diagram of the system has been plotted. It has been determined that the section is simple eutectic type, with coordinates of eutectic points makinq up 30 mol % and 750K. In SnPbSb4S4Sb2S3 quasi binary section at room temperature on basis of initial components, 10 mol % limited solution area was determined from both sides.