We have investigated post-annealing effects of photoluminescence (PL) properties in GaAs/AlGaAs QDs fabricated by modified droplet epitaxy. The annealing temperatures were changed between 520 degreesC and 760 degreesC. The PL intensity of QDs: increased drastically with the increase of annealing temperature. The PL intensity of QDs after the annealing at 760 degreesC was enhanced by two orders of magnitude as compared to that of before post-annealing. This sample showed a distinct PL peak even at the room temperature. With the increase of annealing temperatures, the peak energy shifted from 1.646 to 1.749 eV, continuously. These effects may be caused by improving the crystallinity of QDs systems and the size reduction and:or changing the composition of QDs by the post-annealing.