Provided is a fatty acid derivative-polymer conjugate comprising a conjugate comprising a fatty acid derivative and an alkyl-substituted polylactic acid compound. Also provided is a pharmaceutical composition comprising the conjugate.脂肪酸誘導体とアルキル置換ポリ乳酸化合物を含む結合体を含む、脂肪酸誘導体-ポリマー結合体を提供する。また、該結合体を含む医薬組成物を提供する。