Understanding glacier mass balance (MB) change under global warming is important to assess the impact of glacier change on water resources. This study evaluated the applicability of a modified distributed surface energy balance model (DSEBM) with 3-h temporal and 100-m spatial resolution to the alpine Dongkemadi Glacier (DKMD) in the central Tibetan Plateau region, analyzed the causes of glacier MB variations with respect to energy balance, and evaluated MB changes under various climate scenarios. Results showed that: (i) the modified model can describe surface energy and MB of XDKMD well; (ii) net shortwave and longwave radiation, accounting for more than 80% of total heat flux, dominated the glacier energy balance during both summer and winter months; (iii) summer MB spatial patterns dominated annual MB, consistent with the fact that DKMD is a summer accumulation type glacier; and (iv) effect of increase in air temperature on glacier MB is higher than that of decrease in air temperature. The sensitivity of MB revealed by the modified DSEBM can help to understand MB changes influenced by the climate changes and to regulate water management strategies to adapt to climate changes at the catchment scale.