In the present work, BaTiO3 samples were synthesized by sol–gel method and then they were coated on Si substrate for 30 min at 1500 rpm. The samples were finally calcined at T1 = 85 C, T2 = 200 C, T3 = 400 C and T4 = 600 C to investigate temperature effects on them. The nano structural and nano compositional properties of the samples were also investigated by using thermo gravimetric analysis, X-ray diffraction (XRD), scanning electron microscopy, energy dispersive X-ray, X-map and atomic force microscopy techniques. According to XRD technique, the particle’s sizes were 10–38 nm. The BaTiO3 particles size increased relatively with increasing temperature. According to Fourier transfer infrared radiation technique, the junctions between Ba, Ti and O were strong. In this research, current–voltage (I–V), capacitance–voltage (C–V) and current density–voltage (J–V) curves were used for determining temperature effects on electrical properties of BaTiO3 nanostructure. Dielectric constant and impedance (Z) of BaTiO3 samples were investigated, as well.