Brain and other central nervous system (CNS) cancer is the 10th leading cause of death around the world. To determine the type and grade of brain tumor, brain biopsy is the gold standard. This project aims to develop a semi-autonomous stereotactic brain biopsy robotic system that can helps to shorten the operation time, improve biopsy yield success rate, and enhance the surgical safety. Meanwhile, it helps to shorten the learning curve and reduces operation variances among surgeons.