Garlic (Allium sativum Linn) is a bulbous plant that contains several metabolites such asallicin, diallyl disulfide and trisulfidedially, aminoacids, sterols, saponins, alkaloids, flavonoids, triterpenoids. Base on previous research, saponin, metabolites could reduce formaldehyde contained in the food through the process of saponification. This research aimed to prove that the saponins in garlic could reduce levels of formaldehyde in the tofu. This research is an experimental laboratory with a group pretest posttest design. Tofu samples was taken with purposive sampling method at KM.5 traditional market. Sample were analyzed by qualitative and quantitatif used schiff reagent. Samples of tofu were given two treatments at the storage temperature of cold storage (2-8º C) with 4 variations garlic suspension concentration (10 %, 15 %, 20 % and 25 %) by the immersion for 60 minutes. Analyzed of quantitative by measurement were performen by spectrofotometerUv-Vis. The research showed that consentration of formalin in samples A, B, and C were 23,02 ppm, 24,94 ppm and 17,78 ppm. The results of Pearson and Spearman test showed a significant correlation between garlic suspension (Allium sativum Linn) and storage temperature to level of formalin with p<0.050. Based on this reasearch it could be concluded that the immersion of garlic suspension (Allium sativum Linn) could reduced levels of formalin in the tofu. Increasing the concentrations of garlic suspension was proved to the decreased levels of formaldehyde in the sampl