A vector for targeted delivery of drugs into estrogen receptors over-expressed cells is disclosed. The vector of the present invention is mainly about an active targeting delivery carrier which consists of a plurality of nanoparticles including: (i) a plurality of targeted moiety conjugated to the outer surface of the nanoparticles, the moiety being capable of binding with the estrogen receptor of a target cell, and (ii) bioactive agents encapsulated in the nanoparticles or forming complex with the nanoparticles. The targeted moiety of the present invention can also be conjugated to parent drugs for prodrug design.
