Abstract: This investigation attempted to retrieve the emission coefficients of welding arc by an algebraic reconstruction technique(ART).The ART algorithm was programmed with MATLAB language,and a displaced Gaussian model was used to validate the efficiency of the program.The intensities of a free burning arc were acquired by the imaging method.The emission coefficients were reconstructed by the developed ART program,and the results were compared to that reconstructed by the extensively used Abel inversion.The results show that the ART algorithm has a high precision and can be used for the reconstruction of emission coefficients of welding arc.