To investigate sea-level rise caused by global warming, it is important to accurately assess polar ice sheets mass balance.Since the Intergovernmental Panel on Climate Change Fourth Assessment Report, new observations of ice-sheet mass balance have been published, with improved computer simulations of the response of ice sheets to ongoing climate change.This paper discusses progress in research into ice-sheet mass balance using satellite altimetry, mass budget, and satellite gravimetry techniques, with special focus on new estimates of ice-sheet mass balance and improved ice-sheet modeling, as well as predicted future ice-sheet changes.Future challenges in the study of ice-sheet mass balance are also discussed.