A fatty acid derivative-polymer conjugate including a conjugate comprising a fatty acid derivative and an alkyl substituted polylactide compound is provided. A pharmaceutical composition comprising the conjugate is also provided.本發明係提供一種脂肪酸衍生物-聚合物共軛物,其包括包含脂肪酸衍生物與經烷基取代之聚乳交酯化合物之共軛物。亦提供一種包含該共軛物之醫藥組成物。