In order to improve the drying quality of apple slices and shorten the drying time, medium and short wave infrared was applied to drying apple slices. The drying experiments were investigated under different drying temperatures, slice thicknesses and radiation distances. Experimental results showed that the drying temperature had a significant influence on the drying processing, while the slices thickness was less significant and the radiation distance was the last. The whole drying procedure appeared a falling rate period. According to Fick’s Second Law, the water effective diffusion coefficient (Deff) was worked out. In medium and short wave infrared drying condition, the Deff ranged from 2.85×10-10 m2/s to 7.24×10-10 m2/s. The activation energy determined from Arrhenius equation was 36.58 kJ/mol. On the other hand, drying temperature had a marked impact on the color changing, while the slices thickness and radiation distance had a little influence on color value. Both high L* value and drying efficiency were ensured when the drying temperatures was 70℃，slice thickness was 5 mm and the radiation distance was 80 mm.