Biocides are widely used in leather production for the purpose of preventing microorganism activity in the soaking process. Biocides include chemical components that are harmful for both human health and environment. In this study, we examined the anti-bacterial activity of different vegetable tannins against bacteria in the soaking float. To this end; tannins of quebracho, mimosa, gall-nut, chestnut and valonia were added to the float for 8h and 24h soaking processes in order to examine the effect of these tannins on bacteria, the results were compared with the control group. Subsequently, gall-nut and chestnut extracts were observed to be effective against bacteria in the float during 8h soaking process, while gall-nut was found to be more effective than other vegetable tannins in 24h soaking period.