GaN-based yellow light-emitting diodes (LEDs) on Si substrates are aged at a direct current density of 50 A/cm2 for 500 h. After the aging process, it can be found that the LEDs have a stable electrical property but their light output power is decayed by 4.01％at 35 A/cm2. Additionally, the aging mechanism of GaN-based yellow LED is analyzed. It is found that the decay of light output power may be attributed to the following two reasons:one is the increase of Shockley–Rrad–Hall recombination and the other is the change of the transport path of holes via V-pits after aging, which may induce the radiative recombination current to decrease. In this paper, not only the aging mechanism of GaN-based yellow LED is investigated, but also a new possible research direction in LED aging is given.