The objective of this research was to study the preparation of purple yam cracker made from purple yam flour that has been dried by blanching it before drying. To analyze the viscosity of the flour and developed into a cracker product. By testing sensory acceptance, chemical composition analysis and the energy received. The results showed that purple yam flour had the highest viscosity 91.92 RVU and final viscosity 113.42 RVU. The development of cracker product, it was found that third formula with 40% of the purple yam flour as a substitute for cassava starch showed that received the highest sensory acceptance scores for appearance, crispness, color, and overall preference. The percentage of moisture content, carbohydrate, ash, total fats, protein and fiber of the cracker were shown at 1.73 ± 0.04, 65.37 ± 1.49, 12.42 ± 0.62, 17.87 ± 0.77, 2.61 ± 0.32 and 1.41 ± 0.47, respectively, while its total energy values derived was 466.39±0.96 kcal.