The ternary system Cu-Si-Ti was investigated using XRD, SEM-EDX, and DTA. The existence of two ternary phases τ1-CuSiTi and τ2-TiSi2-xCux as well as their crystal structures are confirmed. The isothermal section at 800°C is corroborated. From DTA data of equilibrated alloys a reaction scheme linking the isotherm at 700°C with the liquidus surface is derived. Using data on primary crystallisation of as cast alloys a projection of the liquidus surface is proposed.