Quantitative susceptibility mapping (QSM) shows a potential to image subthalamic nucleus (STN) and globus pallidus internus (GPi). However, the image quality of QSM is dependent on the selection of regularization parameter during reconstruction. Here we proposed an approach to determine the optimal regularization parameter for imaging the sub-cortical nuclei at different spatial resolution and field strengths. Optimized QSM images were further compared with the other susceptibility weighted images for visualization of STN and GPi at 3T and 7T. Our results suggest that optimized 7T QSM with spatial resolution of 0.35x0.35x1.0mm3 provides better delineation of STN and GPi.