Dominant hemisphere for language function is the left hemisphere, however patients experiencing aphasia followed by damage to language areas often shows good recovery in the days to weeks to even years after brain injury. According to the duration from brain injury, recovery period of language function in aphasia can be divided into three overlapping periods (acute, subacute, and chronic phase) with different underlying neural mechanisms. During subacute period of weeks to months following brain injury, reorganization of neural network through brain plasticity occurring in the both hemisphere plays a crucial role in recovery of language function. Recently, the potential use of functional neuroimaging has been raised to explain the underlying neural mechanism for language recovery, however, the brain areas and various factors affecting brain reorganization are still controversial. This article reviews the clinical evidence for recovery of language function through brain plasticity and reorganization and the factors affecting the recovery of language function in aphasic patients following brain injury.