The present invention provides a hydrogel platform using, as a substrate, hyaluronic acid (HA) conjugated to a pyrogallol (PG) moiety. The HA-PG conjugate of the present invention can be promptly crosslinked by two different methods, such as using an oxidant or adjusting pH. The hydrogel of the present invention can efficiently control physical characteristics, such as a crosslinking rate, elasticity, and adhesive strength, according to the crosslinking manner of each, while having excellent biocompatibility. The hydrogel of the present invention can be used, on the basis of such excellent stability and functionality thereof, in various fields including drug delivery, biopharmaceutical materials such as a wound healing agent or anti-adhesive agent, medicines, and cosmetic products.
