By the methods of DTA, XRD, MSA, as well as by measuring the microhardness and determining the density of the alloys, the CuTe-As 2 Te 3 system was studied and a phase diagram was constructed. The system state diagram is of the eutectic type and is characterized by one chemical compound of Cu 3 As 4 Te 9 composition. Compounds Cu 3 As 4 Te 9 melts incongruently at 320 °C. Solid solutions based on As 2 Te 3 reaches 8mol. % and based on CuTe solid solutions are practically not installed. Cu 3 As 4 Te 9 and As 2 Te 3 form a eutectic composition of 45mol. % As 2 Te 3 and temperature of 265 °C.