This study was conducted to investigate the characteristics of meso-scale combustion. The technique of electrical capacitance tomography (ECT) was used to locate flame position and monitor the effect corresponding to varied air/fuel ratio in a meso-scale combustor. Combustion phenomena including igniting, quenching and unsteady combustion have been visualized using ECT. The method of metallization protecting ECT sensor from high temperature damage and the novel calibration method adapted to ECT monitoring of unknown permittivity flame have been shown to be successful. At the same time, electrical nature of combustion and dielectric characteristics of hydrocarbon flame were studied. The relationship between flame permittivity and state parameters of combustion gas was demonstrated preliminarily.