The results of the manufacturing of instant sweet potatoes from Korea native sweet potatoes and researching nutritional aspects from it. 1. The optimum cooking time for the manufacturing of instant sweet potatoes are 30 minutes, then it water contents are 5%. 2. Along to increasing cooking time, the contents of saccharides and another nutritive is increased, and it has almost constant value in the contents of saccharides. 3. Instant sweet potatoes are a good vitamin food because Vitamin C n the sweet potatoes is destroyed a little through cooking process, but instant sweet potatoes contain much of Vitamin C more than cereal, as 0.146%.