PURPOSE: Hydrogel is provided to have biocompatibility, biodegradation, and thermal stability without toxicity and to effectively be used as a drug delivery system. CONSTITUTION: Hydrogel contains a compound of chemical formula 1 as a crosslinking site. The hydrogel has one of compounds of chemical formulas 2-4 as a repeat unit. A method for preparing the hydrogel comprises the steps of: adding a compound with two or more hydroxyl groups at the ends to a solution in which phosphorous oxychloride is dissolved and reacting； and adding a compound of chemical formula 10 to the reacted material. A drug delivery system contains the hydrogen and a pharmaceutically active ingredient which is encapsulated in the hydrogel.본 발명은 하이드로젤 및 이를 이용한 약물 전달체에 관한 것이다. 본 발명의 일 예시로서 생체 적합성, 생분해성 및 열적 안정성을 가지고, 독성이 없는 하이드로젤 및 이의 제조 방법을 제공하며, 상기 하이드로젤을 이용하여 약물 전달체로서 효과적으로 사용할 수 있다.
