The dielectric relaxation properties and freezing behavior of polar nanoregions (PNRs) of 0.24Pb(In1/2Nb1/2)O-3-0.47Pb(Mg1/3Nb2/3)O-3-0.29PbTiO(3) single crystals have been studied. The Burns temperature T-B, permittivity maximum temperature T-m, and freezing temperature T-f were determined, respectively. It was found that the temperature-dependent dielectric constant can be well described by the Lorenz-type relationship in the ergodic phase due to the existence of PNRs. The diffuseness factor is >30 and is basically not dependent on crystal orientation. The frequency dependence of T-m obeys the Vogel-Fulcher relationship. The residual effect of the poling electric field disappears and the remnant polarization has a sharp decrease near the freezing temperature T-f.