It has become a multidisciplinary research area to overcome cognitive decline caused by aging. Many factors can affect cognitive aging and the influence of second language learning (L2 learning) cannot be ignored. The recent decade has witnessed much pathological, behavior and neuroimaging research that L2 experience may help maintain the cognitive function in the elderly, resist cognitive decline, and even delay the onset of Alzheimer's disease (AD). This work is to review available literature concerned and elucidate the neural mechanisms under which L2 learning (training) may modify or sculpt the brain from perspectives