Modification cassava or commonly known as Mocaf flour has the potential to be used as a substitute for tapioca in crackers making. Mocaf flour also has a higher protein and fibre content compared to the tapioca flour. This study was conducted to determine the effect of tapioca flour substitution with a mocaf in making tofu waste crackers. This study aims to determine the dry basis and carbohydrate levels of tofu waste crackers in several variations of mocaf substitution and the influence of mocaf substitution on the organoleptic properties of tofu waste crackers. The design used in this study was a Completely Randomised Design (CRD) with data analysis using Analysis of Variants followed by Tukey’s Test. Variations in treatment were 0%, 25%, and 50% of mocaf substitution. The parameters analysed were the water content (by the Thermogravimetry method), carbohydrate levels (by the Luff-Schoorl method), and the preference level test for tofu waste crackers. The results showed that the water content of tofu waste crackers in mocaf substitution 0% was 12.3%, and mocaf substitution 25% was 12%, while mocaf substitution 50% was 13.3%. The result of the carbohydrate content of 0% mocaf substitution was 1.47%, and 25 % mocaf substitution was 1.26%, while 50% mocaf substitution was 1.85%. Preference level on tofu waste crackers mocaf substitution showed that the most preferred crackers were tofu waste crackers with 25% mocaf substitution, which was quite brown, slightly scented in mocaf, had a sufficiently crispy texture, and was quite mocaf in taste.