In this study, the antioxidant potential and hydroxymethylfurfural formation of damson plum were investigated using different drying methods. Before drying, the samples were immersed in 1% NaOH at 55°C for 1 min and divided into two groups (half and whole) and dried under the sun and using different microwave power levels (450, 720, 900 W) to reduce the moisture content to 18%. Total dry matter, drying period, total monomeric anthocyanin, total flavonoid, total phenolic, antioxidant capacity and hydroxymethylfurfural values were determined. The sun-drying period of whole plums found to be about four times longer than half plums. Similarly, at different microwave power levels (450, 720 and 900 W), the drying period of whole plums was also longer than half plums, but the sun drying for whole plums was more than 500 times longer and 150 times longer than microwave drying for half plums. Also, the increase in microwave power level shortened the time. The total anthocyanin, total flavonoids, total phenolic and antioxidant capacity values of sun-dried samples were lower than those of microwave-dried samples. It was observed that hydroxymethylfurfural values in microwave-dried samples increased. It is thought that microwave drying at 900 W, where the antioxidant properties of plums dried at three power levels are better preserved, can be recommended with little difference in drying period in 720 W microwave application.