Wetting of polycrystalline W substrates by a molten Zr55Al10Ni5Cu30 alloy was studied using a modified sessile drop method at 1123-1173 K in high vacuum. Good wettability with final stable contact angles of 4-11 degrees, was observed. The Zr adsorption at the solid-liquid interface and further diffusion to the front of the triple line should be the primary reason for the enhanced wettability and the formation of a diffusion band. Moreover, the interfacial microstructure is dictated by temperature. A higher temperature substantially promotes the dissolution of W into the liquid alloy and then precipitation of the W2Zr phase. Accordingly, the processing temperature should be accurately controlled in preparation of the Zr-base bulk metallic glass (BMG) matrix composites reinforced by W particulates or fibers. (C) 2008 Elsevier B.V. All rights reserved.