The aim of this work was to investigate the anti-tumor effect of paclitaxel (PTX)-loaded methoxy poly(ethylene glycol)-poly(ɛ-caprolactone) nanoparticles (MPEG-NP/PTX) against glioblastoma multiforme (GBM). MPEG-NP/PTX was prepared by the emulsion and evaporation technique with particle size of 72.5±2.2nm and did not change remarkably during the period of 21-day storage at 4°C. The drug-loading coefficient and encapsulation ratio of optimized formulation were 8.2±0.6% and 90.4±2.3%, respectively. The in vitro release behavior exhibits a biphase release manner and was affected by PEG segment. In vitro cytotoxicity was assessed using C6 cell lines and was compared to Taxol and PTX-loaded poly(ɛ-caprolactone) conventional nanoparticles (NP/PTX). Cell viability assay against C6 cells exhibited higher or at least comparable cytotoxicity than that of Taxol and NP/PTX. More importantly, in vivo real-time fluorescence imaging analysis in intracranial C6 glioblastoma bearing mice showed that the methoxy poly(ethylene glycol)-poly(ɛ-caprolactone) nanoparticles (MPEG-NP) displayed much stronger fluorescence signal and 3-fold larger Area-Under-Curve (AUC) than poly(ɛ-caprolactone) conventional nanoparticles (NP) in tumor-bearing brain. Furthermore, in vivo anti-glioblastoma effect exhibited the mean survive time of MPEG-NP/PTX (28 days) was much longer than those of Taxol injection (20 days) and NP/PTX (23 days). Therefore, MPEGylated poly(ɛ-caprolactone) nanoparticles significantly enhanced the anti-glioblastoma activity of PTX and might be considered a promising drug delivery system against advanced glioblastoma.