Studies of the influences of temperature, hydrostatic pressure and frequency on the dielectric constant (ε r) and loss (tan δ) of PbNb(Zr,Sn,Ti)O3 antiferroelectric ceramics, have provided a detailed view of the ferroelectric (FE) response and phase transitions of this important material. With the increasing temperature, PbNb(Zr,Sn,Ti)O3 ceramics undergoes successive phase transitions: tetragonal antiferroelectric phase → rhombohedral ferroelectric phase → cubic paraelectric phase. The AFE/FE and the FE/PE phase transition temperature of the antiferroelectrics increased with increasing pressure. Hydrostatic pressure dependence of ε r and tan δ under different phases was also obtained. [ABSTRACT FROM AUTHOR]