- Polysaccharides have emerged as important functional materials because of their unique properties such as biocompatibility, biodegradability, and availability of reactive sites for chemical modifi cations to optimize their properties. The overwhelming majority of the methods to modify polysaccharides employ random chemical modifi cations, which often improve certain properties while compromising others. On the other hand, the employed methods for selective modifi cations often require excess of coupling partners, long reaction times and are limited in their scope and wide applicability. To circumvent these drawbacks, anilinecatalyzed oxime formation is developed for selective modifi cation of a variety of polysaccharides through their reducing end. Notably, it is found that for effi cient oxime formation, different conditions are required depending on the composition of the specifi c polysaccharide. It is also shown how our strategy can be applied to improve the physical and functional properties of alginate hydrogels, which are widely used in tissue engineering and regenerative medicine applications. While the randomly and selectively modifi ed alginate exhibits similar viscoelastic properties, the latter forms signifi cantly more stable hydrogel and superior cell adhesive and functional properties. Our results show that the developed conjugation reaction is robust and should open new opportunities for preparing polysaccharide-based functional materials with unique properties.