The aim of this study is to estimate the influence of water vapor environment on the nanotribological properties of carbon nanotubes coatings. They consist of perpendicularly aligned Multi Wall Carbon NanoTubes (MWCNT) with about 20 nm in diameter and 5 µm long, deposited on the Si (001) substrate by Chemical Vapor Deposition. Experiments were performed with an Atomic Force Microscope under varying relative humidity (0% to 100%). Through normal and lateral modes, adhesion and friction forces between the sample and the gold tip were measured respectively. The coatings present very low adhesion to the tip independently of humidity, probably due to the absence of water meniscus, linked to nanotubes' high hydrophobicity. High friction coefficients of 1~2 have been measured, irrespective of the humidity. A difference of surface chemistry between top and wall of nanotubes, bending behavior during friction, or transfer of nanotubes to the tip may relate to this anomalous tribological property.