[en] Orthophosphate KPb₄(PO₄)₃ compound was synthesized by the conventional solid-state reaction. The phase formation of the compound was confirmed from the powder X-ray diffraction. Vibrational study confirms the existence of [PO₄]³⁻ group. The impedance spectroscopy measurements was realized with Compact disc, Φ = 8 mm diameter and 1.2 mm thickness in the range temperature (659–708)K and frequency (209 Hz–1 MHz), respectively. As well, the impedance spectra are well adjusted to an equivalent circuit formed by a serial combination of three cells. It was found that the non-overlapping small polaron tunneling (NSPT) model is suitable to describe the conduction mechanism in this compound. - Highlights: • Ac conductivity data affirm that for high frequencies σ_ac is proportional to ω^s. • The non-overlapping small polaron tunneling is the appropriate conduction mechanism of KPb₄(PO₄)₃ compound. • The KPb₄(PO₄)₃ phosphor was prepared by the conventional high temperature solid-state reaction. • Electrical properties of the compound have been studied using complex impedance spectroscopy in the frequency range 209 Hz–1MHz and temperature range (659–708)K.