Crystalline Cu-Zr alloys of various composition were annealed (200-400℃) in ultra-high vacuum and in hydrogen, and their surface composition was analyzed by X-ray photoelec-tron spectroscopy. Contrary to the mostly observed oxygen induced surface segregation of Zr we found strong Cu segregation after annealing Cu-rich sample in hydrogen atmosphere. Scanning electron micrographs show surface Cu precipitates, apparently formed due to the effect of the heat of chemisorption of hydrogen on Cu.