The effect of ultrasonic (US) treatment on electroluminescence of initial and irradiated with 2-MeV electrons (Φ = 8.24·10¹⁴ e/cm²) GaAs-GaP LEDs grown on solid solution base was studied. It was found that luminescence intensity of samples previously loaded with US increased during long-term storage (t = 15 h). Passing the current through the diode generates the relaxation process of radiation brightness falling followed by the growth when ultrasound is switched on. The results of calculation of the dislocation density responsible for electroluminescence quenching within the region of electroluminescence degradation are adduced. It was found the ultrasound effect on diodes irradiated with high-energy electrons.