Abstract: The liquidus of the Sn-rich range in the phase diagram of Cu-Zn-Sn system has been investigated by means of thermal analysis and X-ray diffraction method. It was found that there are five surfaces corresponding to the primary crystalliza- tion of Sn, η-Cu_6Sn_5, ε-Cu_3Sn, ε-CuZn_(~6), and η-Zn respectively and three invariant points: E, the ternary eutectic point, (90.8 Wt.%Sn, 0.2wt. %Cu; 190 ℃) and two ternary peritectic points P_1(91.3Wt.%Sn, 5.8Wt.%Cu; 358 ℃) and P_2(~0.2 Wt. %Cu, 96.3Wt. %Sn; 218 ℃) in the Sn-rich range. No ternary intermetallic compound was detected.