Fettuccine is a long pasta made from semolina flour, wheat flour, and egg. Semolina flour and wheat flour import has been increased every year and they are known as a high gluten and low resistant starch product. Purple sweet potato flour could be an alternative for decreasing consumption of gluten and import of semolina and wheat flour. The aim of this research was to determine the effect of cooling for purple sweet potato flour resistant starch and the effect of wheat and semolina flour ratio towards fettuccine characteristics. In this research, resistant starch content, proxymate analyses and some properties of purple sweet potato flour and fettuccine were characterized. The result of this research showed that 24 hours cooling on purple sweet potato give the highest resistant starch content. The best purple sweet potato flour consist of 4.45% resistant starch content, 30.17% yield, 3.21% moisture content, 1.27% protein, 0.93% fat, 1.87% ash, 17 and 21o as the highest peak for x-ray diffraction and type C crystals. Fettuccine made from 20.01% of purple sweet potato flour and 3:1 ratio of wheat flour with semolina flour was the best formulation based on sensory result. This formulation has 4757.62 gram hardness, 35.85 lightness, and contains 1.89% resistant starch content, 5.91% moisture content, 3.36% ash, 15.91% protein, 4.74% fat, and 70.24% carbohydrates with 23o as the highest peak for x-ray diffraction and type C crystals. / Fettuccine adalah produk pasta yang memiliki bentuk panjang dan pipih yang terbuat dari tepung terigu, tepung semolina, dan telur. Tepung terigu dan tepung semolina merupakan produk yang terus meningkat aktivitas impor setiap tahunnya. Tepung terigu dan tepung semolina juga dikenal memiliki tingkat gluten yang tinggi dan kadar pati resisten yang rendah. Tepung ubi jalar ungu menjadi alternatif dalam menurunkan konsumsi gluten dan menurunkan nilai impor tepung terigu dan tepung semolina. Tujuan dari penelitian ini mengetahui pengaruh pendinginan untuk kadar pati resisten tepung ubi jalar ungu dan pengaruh konsentrasi tepung ubi jalar ungu dan rasio tepung terigu dengan semolina terhadap karakteristik fettuccine Hasil penelitian menunjukkan tepung ubi jalar ungu yang didinginkan 24 jam menghasilkan kadar pati resisten tertinggi. Tepung ubi jalar ungu terbaik memikili kadar pati resisten 4,45%, rendemen sebesar 30,17%, kadar air 3,21%, protein 1,27%, lemak 0,93%, abu 1,87%, sudut tertinggi pola difraksi 17 dan 21o, dengan tipe kristal pati C. Formulasi fettuccine dengan penggunaan 30% tepung ubi jalar ungu dan rasio rasio tepung terigu dengan tepung semolina 3:1 menjadi formulasi terbaik fettuccine ubi jalar ungu. Formulasi fettuccine terbaik memiliki nilai hardness 4757,62 gram, lightness 35.85, kadar air 5,91%, kadar abu 3,36%, protein 15,91%, lemak 4,74%, dan karbohidrat 70,24% dengan sudut pola difraksi tertinggi 23o dan tipe kristal pati C.