Saluran pencernaan akan rentan terkena berbagai macam penyakit apabila terlalu sering mengonsumsi makanan rendah serat dan tinggi lemak. Mengonsumsi minuman probiotik merupakan salah satu cara untuk menghidari terjadinya masalah pencernaan. Pada penelitian ini, minuman probiotik dibuat dari sari tape ubi jalar ungu yang difermentasi menggunakan Lactobacillus casei. Riset ini bertujuan untuk mengetahui potensi tape ubi jalar ungu sebagai minuman probiotik. Metode yang digunakan yaitu Rancangan Acak Lengkap (RAL) dengan 4 perlakuan penambahan L. casei yaitu K (0%), A (2%), B (4%) dan C (6%) serta 3 kali ulangan. Hasil riset menunjukkan, perlakuan terbaik yaitu penambahan L. casei 6% dengan total BAL 9.42 Log cfu/ml, ALT 9.53 Log cfu/ml, nilai pH 3.93, total asam 0.43%, antosianin 64.71% dan antioksidan 65.70%. Hasil uji organoleptik warna 2.97 (agak suka), aroma 2.99 (agak suka) dan rasa 2.35 (tidak suka). Nilai evaluasi menunjukkan bahwa minuman sari tape ubi jalar ungu berpotensi dikembangkan sebagai minuman probiotik.The digestive tract will be susceptible to various kinds of diseases if eat too often low-fiber and high-fat foods. Consuming probiotic drinks is one way to avoid digestive problems. In this study, a probiotic drink was made from purple sweet potato tape fermented using Lactobacillus casei. This research aims to determine the potential of purple sweet potato tape as a probiotic drink. The method used was Completely Randomized Design (CRD) with 4 additional treatments of L. casei, namely K (0%), A (2%), B (4%) and C (6%) and 3 replications. The results showed that the best treatment was the addition of 6% L. casei with a total LAB of 9.42 log cfu/ml, ALT 9.53 log cfu/ml, pH value 3.93, total acid 0.43%, anthocyanins 64.71% and antioxidants 65.70%. The results of the organoleptic test were 2.97 (slightly like), aroma 2.99 (slightly like) and taste 2.35 (dislike). The evaluation value shows that purple sweet potato tape drink has the potential to be developed as a probiotic drink.