In this paper, a type of redox-sensitive mesoporous silica nanoparticles functionalized with polyethylene glycol (PEG) through a disulfide bond linker (MSNs-SS-PEG) was successfully synthesized with silica nanoparticles modified by thiol group (MSNs-SH) and thiol-functinalized methoxy polyethylene glycol (MeOPEG-SH). Meanwhile, the particle size, pour size and structural properties of these materials were characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), dynamic light scattering (DLS), fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and nitrogen adsorption-desorption measurements. Furthermore, the in vitro drug release behaviour of DOX-loaded MSNs-SS-PEG (DOX@MSNs-SS-PEG) was investigated. It was shown that DOX release was markedly accelerated with the increasing concentration of glutathione (GSH), while DOX was not released from the carrier materials in the absence of GSH. Cytotoxicity evaluation revealed the good biocompatibility of the blank nanoparticles and the DOX@MSNs-SS-PEG exhibited the comparative anticancer activity compared with free DOX towards BEL-7402 cells. Therefore, the MSNs-SS-PEG might be a great potential carrier as the anticancer drug delivery.PEG was highly biocompatible and the DOX loaded nanoparticles possessed comparative anticancer activity with the free DOX towards BEL-7402 cells. These results demonstrated that MSNs-SS-PEG would be a great potential carrier for anticancer drug delivery.