Ternary compounds (PbTe)1-x(SnTe)x with nanocrystallines were synthesized at a temperature of 180oC by conventional solvothermal method. XRD analyses revealed that relatively pure compounds can be synthesized using ethylenediamine as a solvent only when a reaction time of at least 24h is applied. The XRD results are in agreement well with those from EMPA analysis. The grain sizes of the materials, ranging from 50~70nm, are slowly increased with reaction time. Measurements showed that the maximum power factor of about 6.0×10-4 W.m.K-2 for the synthesized materials are higher than that of similar material prepared by vacuum melting.