Sarennes glacier (SAR) is located in the Grandes Rousses massifn (France), between 2900 and 3200 m altitude. Survey on this glacier is the longest record of glacier mass balance in France, including also winter and summer mass balance. Data series are continuous and cover few decades. This site is also characterized by the complete glaciological parameters performed annually to complete annual and seasonal mass balance: ice velocity, ice thickness variation, snout position. SAR is a part of the French Glacier Observatory GLACIOCLIM/CRYOBS-CLIM.