Photodynamic therapy (PDT) is considered an innovative and attractive modality to treat ovarian cancer. In the present study, a biodegradable polymer poly (ethylene glycol) (PEG)âpoly (lactic acid)(PLA)âfolate (FAâPEGâPLA) was prepared in order to synthesize an activeâtargeting, waterâsoluble and pharmacomodulated photosensitizer nanocarrier. Drugâloading content, encapsulation efficiency, in vitro and in vivo release were characterized, in which hypocrellin B (HB)/FAâPEGâPLA micelles had a high encapsulation efficiency and much slower control release for drugs compared to free drugs (P < .05). To evaluate the targeting ability of the HB/FAâPEGâPLA micelles, a cellular uptake study in vitro was carried out, which showed significantly enhanced uptake of HB/FAâPEGâPLA micelles in SKOV3 (FR+) compared to A2780 cancer cells (FRâ). The enhanced uptake of HB/FAâPEGâPLA micelles to cancer cells resulted in a more effective postâPDT killing of SKOV3 cells compared to plain micelles and free drugs. Binding and uptake of HB/FAâPEGâPLA micelles by SKOV3 cells were also observed in vivo after ip injection of folateâtargeted micelles in tumorâbearing ascitic ovarian cancer animals. Drug levels in ascitic tumor tissues were increased 20âfold (P < .001), which underscored the effect of a regional therapy approach with folate targeting. Furthermore, the HBâloaded micelles were mainly distributed in kidney and liver (the main clearance organs) in biodistribution. These results showed that our newly developed PDT photosensitizer HB/FAâPEGâPLA micelles have a high drugâloading capacity, good biocompatibility, controlled drug release, and enhanced targeting and antitumor effect, which is a potential approach to future targeting ovarian cancer therapy.