The ternary system Sn1-x-yMnxSbyO2(y=0.05) solid solutions were prepared by chemical coprecipitation method.The phase compositions of these type solid solutions during 600-1000 ℃were analyzed using XRD and TG-DTA.The subsolidus phase diagram of Sn1-x-yMnxSbyO2(y=0.05) solid solutions was obtained by the results of XRD and TG-DTA analysis.The formation mechanism of Sn1-x-yMnxSbyO2(y=0.05) solid solutions was emphatically investigated.The results showed that there is only quartet SnO2 rutile phase existence in the Sn0.9Mn0.05Sb0.05O2 solid solution during 600-1000 ℃ annealing temperatures,Sb and Mn are mainly in the form of Sb5+、Mn3+ and Mn4+ entering the SnO2 lattice to form a limited solid solution.There are cubic bixbyite Mn2O3 phase existence in the Sn0.7Mn0.25Sb0.05O2 and Sn0.6Mn0.35Sb0.05O2 solid solution at 700 ℃ and 800 ℃,Mn3O4 phase existence at 1000 ℃,respectively.Besides,there are Sb3+Sb5+O4 phase existence in the Sn0.6Mn0.35Sb0.05O2 solid solution at 1000 ℃.The solidus phase diagram of Sn1-x-yMnxSbyO2(y=0.05) solid solutions contain six regions.The quartet SnO2 single-phase zone is(Sn,Mn,Sb)O2ss solid solution(Sb or Mn are in the form of Mn2O3 and Sb2O5 incorporated into the SnO2 lattice and reached saturation) which could be used as a good electrical conductivity and corrosion resistance of the anode materials,mesosphere.