Abstract: The upward-casting process, to manufacture Cu-Ag alloy contact wire, and its product properties were investigated experimentally. The results showed that the electromagnetic stirring effect in the upward-casting process can improve the homogeneity of alloy composition prominently, by which the deviation of Ag mass fraction can be reduced down to 0.01% or only half by other methods. Tests with the samples of Cu-Ag alloy contact wire showed that the main properties of Cu-Ag alloy contact wire are better than those of the pure copper one, i.e., higher breaking load, lower elongation and slightly lower conductivity with the increasing Ag content. Its plasticity decreased notably when Ag mass fraction exceeds 0.12%. As to the softening temperature, the alloy wire is about 100°C higher than that of the pure copper one - it is of far-reaching importance to safe railway running and wire's service life. In view of the wholeness of properties, the Ag mass fraction of Cu-Ag alloy contact wire should be kept from 0.1% to 0.12%.