Cold-air drying was conducted for a steamed pumpkin-sweet potato slab to improve its quality, convenience, and preference as a snack. A steamed pumpkin-sweet potato slab was dried from 10 to $25^{circ}C$ for 48 h, and its moisture content, color, texture, and taste at different drying temperatures and drying times were evaluated. The lowest moisture content was 4.98%, at $25^{circ}C$. The lightness decreased, but the other color values (a, b, and ${Delta}E$) increased with the increasing drying temperature and drying time. The reducing sugar and soluble solid ranged from 98.7 to 194.75 mg/g and 19-70 $^{circ}Brix$, respectively. The highest hardness of the steamed pumpkin-sweet potato slab was 23.88 $kg_f/cm^2$, and the springiness and cohesiveness were 91.15 and 98.36% when it was dried at $25^{circ}C$ for 48 h. The sensory evaluation score was high at $10^{circ}C$, 40 h and at $25^{circ}C$, 24 h. The optimum drying condition was predicted at $19^{circ}C$, 32 h via response surface methodology (RSM).