Three types of surfactant-templated mesoporous silica nanoparticles (Surf@MSNs) of 150-660 nm in diameter were developed as anticancer drug delivery systems. The Surf@MSNs exhibit the high drug (surfactant) loading capacities, the sustained drug (surfactant) release profiles and the high and long-term anticancer efficacy. The effects of the Surf@MSNs concentration, the type of the contained surfactants and the incubation time on the cytotoxicity and proliferative activity of MCF-7 cells were evaluated. A common anticancer drug CPT-11 was also loaded into surfactant-free MSNs (CPT@MSNs) and used as a reference for estimating the anticancer efficacies of Surf@MSNs. Surfactant-extracted MSNs exhibited neglectable cytotoxicity to MCF-7 cell, and free surfactants exhibited higher cytotoxicity than free CPT-11 at the same concentration. The endocytosis enhanced the drug uptake by MCF-7 cells and the anticancer efficacies of Surf@MSNs and CPT@MSNs, and more surfactants would be released in a longer term, which led to the more significant enhancement of the cytotoxicity, than CPT-11 with the process of incubation. Among the investigated Surf@MSNs, CTAB-contained MSNs (CTAB@MSNs) show remarkably higher long-term anticancer efficacy than CPT-11-loaded surfactant-free MSNs (CPT@MSNs), even at very low concentrations of 2-15 microg mL(-1).