Transport study of zidovudine (AZT) and lamivudine (3TC) loaded on polyburylcyanoacrylate (PBCA) and methylmethacrylate-sulfopropylmethacrylate (MMA-SPM) nanoparticles (NPs) across the in vitro blood-brain barrier (BBB) model system was presented. Through primary culture, confluent monolayer of bovine brain-microvascular enclothelial cells (BBMECs) with the feature of cellular homogeneity and tight intercellular junction was demonstrated by immunocytochemical fluorescent method. Besides, for the colloidal drug-carrier system, average diameters of the two nearly monodispersed PBCA and MMA-SPM nanospheres were, respectively, about 92 nm and 78 nm. The amount of AZT and 3TC across the current BBMEC monolayer in carrier-incorporated system was much higher than that in non-carrier system, suggesting sufficient amelioration in drug transport by employing the NP carriers for brain-targeting delivery. Comparing PBCA NPs with MMA-SPM NPs, the amount of drug (AZT and 3TC) across the in vitro BBB system for the former was in excess of 1.5 times that for the latter.