The molecular distribution and diffusion of water confined in hydrophobic nanopores were studied by molecular dynamics simulations (MD). We found these water molecules have some unusual behavior than that of the bulk. The density profiles are extremely inhomogeneous and some vacuums and clusters occur in small-size pores at lower density. The diffusivity in nanopores is much lower than that of the bulk, and it decreases as the pore width decreases. The diffusivity in channel parallel direction (D-x) are 4-10 times larger than that in channel perpendicular direction (D-y, D-z) at higher temperatures. (C) 2003 Elsevier B.V. All rights reserved.