For the Russian Arctic territory, expected changes of multi-annual maximal flow statistics is estimated for the period of 2010-39. Results are obtained for the climate scenarios SRES:A2, SRES:A1B and SRES:B1 for four projections from Global Circulation Models. The method of the long-term estimation of the multi-annual maximal flow statistic is based on stochastic model of a spring flood flow with regional adaptation. For the most part of Arctic, the significant changes of the multi-annual maximal flow are expected. Regions with expected significant changes in multi-annual mean values and variation coefficients are outlined. In such zone, the correction of maximal discharge “upper-tail” valuesis recommended. Examples of maximal dischargesof 1 % probability of exceedance are shown for two catchments.