Glacier changes in Marian Cove, King George Island (KGI) were investigated on the basis of observed and modeled data. Air temperature observations for the past 51 years recorded at the Russian Bellingshausen Station (BS) and aerial photographs provided adequate proofs of glacier retreat and regional warming. One-dimensional numerical simulations with yearly variant mass balance were performed to evaluate the glacier advance and retreat history. Then the models were validated by observed data. The results indicate that the mass balance of 0.6 m a-1 is a threshold point determining glacier advance or retreat in Marian Cove. The glacier changes are mainly affected by the ice thickness at the terminus and the local mass balance. The mass balance also affects glacier displacement in subsequent years. Marian Cove is probably ice-free by 2060 under condition of present warming trend.