Disclosed are therapeutic hydrogels for atopic dermatitis and a method for preparing the same. The hydrogels comprises a biocompatible polymer, a polyalcohol, and a medicinal plant extract. The hydrogels can carry medicinally effective ingredients for a sustained period of time and absorb wound exudates properly. The hydrogels have suitable gel strength and, when applied to a wound, can prevent bacterial infection of the wound. Moreover, the methods employing radiation allow the polymer chains to be crosslinked to each other, and also bring about a sterilization effect in the final hydrogel. There are no problems of toxic residues in the hydrogels. They are easy to attach to the skin and concomitantly provide a cool feeling. Supported by the laminate of hydrophilic non-woven fabric sheet and polyethylene film, the hydrogel retain water for a prolonged period of time and thus are useful in the treatment of contact dermatitis and atopic dermatitis.