The grand canonical Monte Carlo (GCMC simulation study on the separation performance of zeolites (MFI, MOR, CFI and DON) and carbon nanotubes (CNTs) to ethanol-water mixtures is reported. The calculation is performed with different bulk percentage under the ambient temperature and pressure. The results show zeolites prefer water to ethanol and could be used for ethanol dehydration. Only water can enter CNT55, but for other CNTs, because the CNT is more hydrophobic than zeolite, the selectivity of CNTs to ethanol is larger than 1, and CNT77 is very fit to condense dilute ethanol solution. CNT77 show excellent performance for its special nanoscale. It prefers ethanol to water in all fraction range. (C) 2007 Elsevier B.V. All rights reserved.