BiFeO3, BiFe0.9Ti0.1O3 and BiFe0.9Ti0.05O3 ceramics were prepared by solid state reactions and were compared in electrical and dielectric properties. The resistivity of BiFe0.9Ti0.05O3 was 1.3×1012 Ω cm, which was about two and a half orders of magnitude higher than that of BiFeO3. and three times higher than that of BiFe0.9Ti0.1O3. The dielectric loss of BiFe0.9Ti0.05O3 was 0.1 and 0.02 at 100Hz and 1MHz, respectively. These phenomena can be explained base on the decrease of oxygen vacancies VO•• and defect complexes between the ferrum vacancies VFe and oxygen vacancies VO•• in the ceramics.