BiAlO3-doped Ba0.99Ca0.01Zr0.02Ti0.98O3 lead-free piezoelectric ceramics have been synthesized by the mixedoxide route,and their structure and dielectric properties have been investigated.XRD results show all samples are perovskite phase.Dielectric measurements reveal a gradual transformation from a sharp ferroelectric peak to a round dielectric peak with pinched phase transitions,accompanying the increased diffuseness.For the samples with high levels of BiAlO3,the frequency-dependent the temperature at permittivity maxima satisfying the relationship f=f_0 exp[-(E_a ?(k_B T_m))^p ] indicates a relaxor behavior.