Abstract: OBJECTIVE To investigate the cellular uptake and in vivo imaging of paclitaxel(PTX)-loaded polyethylene glycol(PEG)-modified rhein conjugate micelles. METHODS (P4/P2+PTX)/CRmP micelles were prepared by co-loading environment-responsive fluorescent probes P4/P2 and PTX into CRmP micelles. Using MCF-7 cells as cell models, the uptake of the micelles by MCF-7 cells was analyzed by laser confocal microscopy and flow cytometry. The H22 subcutaneous transplanted tumor mice were used as animal models, and the distribution of the micelles in vivo and in vitro were analyzed by in vivo imaging system. RESULTS (P4+PTX)/CRmP micelles in the intact form were internalized by MCF-7 cells and distributed in the cytoplasm. (P2+PTX)/CRmP micelles were more accumulated in the liver and tumor sites in vivo, and gradually accumulated at the tumor sites during the experimental time. CONCLUSION The intact micelles can be taken up by tumor cells, and have liver and tumor targeting properties in vivo.