The leather industry is a huge industry used in the conversion of skin and hides towards usable form. However, due to toxic chemical contents, it has great pollution abundance in the world. Previous studies deal with how biopolymers are used in each respective processing stage as cleaner technologies. However, there was little information about compressive research on bio-polymers in leather processing. So this paper uses Google Scholar for studies and to grasp information related to biopolymer applications. Innovations regarding the natural polymers' advantage in the leather processing stage solve the problem related to pollution. Among them, carbohydrates, protein and carbohydrates as soaking agents, keratin as unhairing agents, starch as tanning agents, starch and keratin as fillers, and keratin as finishing agents play a role in the processing stages. To sum up, this study focuses on the application of natural polymers in the leather processing industry.