UHMWPE fibers have widely application, but the poor adhesion to polymer matrix limit its development. Polymerization of vapor phase pyrrole on UHMWPE fibers was introduced in this paper for improve the adhesion between UHMWPE fibers and epoxy. The Ppy-coated UHMWPE fiber was studied by SEM, FTIR, DSC and pullout test, respectively. The result showed that there is no chemical act between UHMWPE fiber and polypyrrole. The Ppy coatings have strong effect on the morphological and adhesion property of UHMWPE fiber. The most important, the maximum pullout force was improved after pyrrole polymerization on the surface of UHMWPE fiber.