Previous studies have revealed that the shear band propagation of metallic glasses can be strongly influenced by decreasing the sample size, leading to the dramatically enhanced plasticity. Here we show that the sample size also affects the shear band fracture behavior. When reducing the sample size, the compressive shear band fracture mode is changed from the typical instant fracture with vein patterns into a gradual fracture mode without the formation of vein pattern. This can be explained by the marked reduction of energy dissipation density during shear band sliding in small samples and thus the enhanced shear band stability against the instable fracture.