In this case study, we investigated the change of cortical excitability and motor function recovery after transcranial direct current stimulation (tDCS). A patient with chronic right middle cerebal artery territory infarction received tDCS. We performed anodal tDCS on her ipsilesional primary motor cortex which was found by motor evoked potential and conventional occupational therapy for 2 weeks. We evaluated upper extremity function with Fugl-Meyer Assessment (FMA) before and after, one and three months after tDCS. In addition, functional magnetic resonance imaging (FMR) was carried out to evaluate the change of cortical excitability. FMA score was improved after tDCS and the improvement was prominent at one and three months later compared to pre-treatment score. And cortical excitability of ipsilesional primary motor cortex was increased after tDCS. As these results show tDCS seems to be useful tool in promoting motor recovery through increasing cortical excitability in stroke patients.