Abstract: Rare earth (RE) treated Carbon nanotube (CNTs) composite thin films were prepared on hydroxylated silicon substrates by a self-assembling process from specially formulated solution. The morphology,composition and structre of the RE-CNTs/APTES-SAM composite films were investigated by scanning electron microscope（SEM）and X-ray photoelectron spectroscopy（XPS）,and the friction properties were determined on a UMT-2MT reciprocating friction and wear tester. SEM observation revealed Non-aligned CNTs in quantity were found on the substrates, XPS analysis revealed CNTs composite films were deposited on oxidized APTES-SAM, making use of the chemical reaction of between RE and phosphonic acid group. The tribological experiment showed that the friction coefficient of composite films was low and little chang with increasing load and sliding velocity. The RE-CNTs/APTES-SAM composite thin films can decrease the friction coefficient of the substrate significantly, indicating its well-behaved abrasion resistance and friction stability