The effect of puffing conditions on the physical properties and sensory evaluations of a puffed snack (ppeongtuigi) made of purple sweet potato flour was investigated. The snacks consisted of coated artificial rice with purple sweet potato flour with water, tempered to 7%, 9% and 11% moisture. The coated material was puffed at 236, 241, or 246oC for 4, 5, or 6 s. The L* value decreased as the heating time increased. The a* and b*values, specific volume, and hardness increased with increasing heating temperature and heating time. Puffed snacks produced under conditions of higher moisture (7%), higher heating temperature (246oC), or longer heating time (5 s) showed high scores for appearance, color, taste, and overall acceptability in sensory evaluations.