Accurate observations of surface mass balance are pivotal for assessing the Antarctic Ice Sheet mass balance and its link to climate dynamics. Studying regional changes in surface mass balance is challenging due to limited on-site observations and the susceptibility of measurements from snow pits and ice cores to localized disturbances. Satellite data and short-term localized measurements suggest no significant changes or a possible increase in surface mass balance across the East Antarctic Ice Sheet in recent decades, but these findings lack large-scale validation. Here we use observations from mass balance stakes to show a significant negative surface mass balance trend along the inland transect from Zhongshan Station to the Antarctic Ice Sheet summit (Dome A) during the period 2005–2020. The mean surface mass balance trend for the inland section over the 15-year period is −2.01 ± 0.37 kg m−2 yr–2, indicating a 35.5