A xPb(Zn1/3Nb2/3)O-3-(1-x)Pb(Zr0.95Ti0.05)O-3 (xPZN-(1-x) PZT) system close to antiferroelectric-ferroelectric (AFE-FE) morphotropic phase boundary has been prepared and investigated. The XRD results reveal PZN addition induces a phase transition from the orthorhombic (AFE) to rhombohedral (FE) phase through a phase coexistence region (AFE+FE). The polarization-electric field (P-E) measurements indicate that the AFE phase can be induced into a metastable FE (FEm) phase. And the FEm can recover to AFE around a critical temperature indicated by temperature-dependent P-E loops. A composition-temperature phase diagram was generalized within a certain range of PZN content in which an AFE-FE phase boundary connecting orthorhombic antiferroelectric to rhombohedral ferroelectric phase zones is formed near room temperature.