The surface acoustic wave(SAW)properties in (1-x)Pb(Zn1/3Nb2/3)O3-xPbTiO3 single crystals poled along c at rhombohedral, tetragonal and morphotropic phase boundary be compared by the Christoffel equation with semi-infinite boundary conditions. The results show that 0.92Pb(Zn1/3Nb2/3)O3-0.08PbTiO3 single crystal near morphotropic phase boundary has better surface acoustic wave properties than the rhombohedral 0.955Pb(Zn1/3Nb2/3)O3-0.045PbTiO3 and tetragonal 0.88Pb(Zn1/3Nb2/3)O3-0.12PbTiO3. It is very apparent that the surface acoustic wave electromechanical coupling coefficient of 0.92Pb(Zn1/3Nb2/3)O3-0.08PbTiO3 single crystal is dramatically higher compared to tetragonal single crystal. Also, 0.92Pb(Zn1/3Nb2/3)O3-0.08PbTiO3 single crystal has low phase velocities and small power flow angles. Therefore, this crystal is very suitable in making SAW devices with superior electromechanical performance.