The impact of the potential functional reorganization in neuronal populations in motor cortical areas during the functional recovery post a Spinal Cord Injury (SCI) remains unclear. In this study, the cortical neuronal data were recorded from a monkey while it was trained to walk bipedally on a treadmill both before and after the spinal cord injury. A neuronal network graph for multiple steps in different sessions was constructed by using the correlation coefficients between different neurons. The global efficiency and the vulnerability of the graph were then evaluated to reveal the intrinsic relation between the changes of the neuronal activity patterns and the functional recovery. The preliminary results indicate that the observed significant changes in the neuronal activity patterns in the motor cortex suggest that the patterns of the functional reorganization (neural plasticity) in the motor areas of the cortex are correlated and they make contributions to the functional recovery.