Abstract: Nano-rod particles spread on the sand-milled Y₂O₃ submicron phosphor particles surface resulted in a reduction of crystallinity and luminescence. It exhibited an abnormally large particle size with a step-like particle surface by furnace annealing at 1400°C–10min with a ramp 10°C/min. The decreased photoluminescence (PL) and crystallinity could be recovered to the original intensity of commercial phosphors by furnace and microwave annealing. The 611nm PL intensity and crystallinity of 900°C with a ramp >40°C/min microwave annealed samples was higher than that of the 1200°C with a ramp 10°C/min furnace annealed ones. The main differences between microwave and furnace annealing were fast smoothing, recrystallization with a limited grain growth and effective activator homogenization at a lower temperature for the microwave annealing.