Purple sweet potato (Ipomoea batatas (L.) Lam) can be used as diversification of carbohydrates based food product and it was rich in antioxidant and dietary fiber. The objectives of this research was to study the effect of substitution (0%, 10%, 20%, 30%, and 40%) of purple sweet potato (flour and mashed) and storage methods (drying and freezing) on the characteristic of flat rice noodle. The first step in this research was used to determine the best rice noodle making method using batter and crumbly making method. The result showed that the best flat rice noodle was produce by batter making method. Batter making method showed higher chewiness than crumbly making method. The substitution of 20% (based on total rice flour) of mashed purple sweet potato gave the best characteristic (chewiness, adhesiveness, color, taste, and flavor) of the flat rice noodle than the others. Purple sweet potato substitution increase the antioxidant activity and dietary fiber. The storage methods affected the flat rice noodles’ characteristic (chewiness, adhesiveness, cooking loss, and color). The freezing storage method showed the best flat rice noodle characteristic. Freezing until week 4 storage showed higher antioxidant activity, lower cooking loss, and microbial safety during storage rather than drying method.