Elevation changes of glacier surfaces were investigated in Rongbuk Catchment (RC) on the northern slopes of Mt. Qomolangma in the central Himalayas, by comparing a digital elevation model (DEM) generated from the 2006 ALOS/PRISM imageries with the base DEM1974 derived from the 1:50,000 topographic maps. The average elevation change rate of glacier surfaces in RC was estimated at -0.47±0.23 m a⁻¹ between 1974 and 2006. Such surface lowering rates varied significantly with glaciers and altitudes. One of the notable results is that the debris-covered ice thinned much more rapidly than the exposed ice at higher altitudes. Overall, glaciers in RC have lost mass of -0.06±0.04 Gt a⁻¹ during 1974–2006. Glacier imbalance constitutes about 50% or more of the Rongbuk runoff.