In this study, a targeted nanoparticle platform for co-delivery of anticancer drugs based on folate-conjugated eight-arm-polyethylene glycol-betulinic acid (F-8arm-PEG-BA) was first presented. F-8arm-PEG-BA was synthesized by introducing target molecules (folate) and drug molecules (betulinic acid, BA) to hydrophilic molecules (8arm-PEG). Then another anticancer drug, hydroxycamptothecin (HCPT), was encapsulated into the self-assembled nanoparticles from the conjugate by a simple nanoprecipitation method. These F-8arm-PEG-BA/HCPT nanoparticles (NPs) had a small size (∼120 nm), acceptable critical aggregation concentration (∼64.8 μg mL-1), and high drug loading (∼18 wt% BA and ∼16 wt% HCPT). Compared to the free drugs, the nanoparticles significantly improved the cellular cytotoxicity and exhibited an obvious synergistic effect by the co-delivery of two different anticancer drugs, BA and HCPT. Pharmacokinetics study revealed the nanoparticles could prolong the circulation of BA and HCPT in the blood. In vivo studies indicated that the nanoparticles enhanced tumor targeting and antitumor activity with lower systemic toxicity. In conclusion, F-8arm-PEG-BA/HCPT NPs have great potential for targeted chemotherapy for cancer.