Measurements of the voltage-current characteristics and space-charge capacitance have been made on the epitaxial p-n junctions grown by method of silicon carbidt crystals sublimation. An analysis of the forward voltage-current and voltage-capacitance charateristics shows that the structures of the p-n junction may vary over a quite wide range, from typical p-i-n junctions to nearly linear graded junctions resulted from different epitaxial growth parameters, but most of them have intermidiate structures. The effect of epitaxial growth parameters on structures of p-n junctions is briefly discussed.In addition, The brightness-current characteristics, the spectral distribution of electroluminescence of forward biased epitaxial p-n junctions, and their performance under pulse and a.c. excitions are also described.