Abstract: Radiosurgery commenced when the Gamma Knife was invented by Lars Leksell in 1951. Thirty yearshave passed since radiosurgery was applied clinically. Millions of patients have benefited from it and haveavoided traditional surgery. Early radiosurgery was frame-based and was mainly used for intracranial lesions,providing excellent clinical results. The linear accelerator-based radiosurgical technique was established inthe 1980s, and radiosurgery entered a new epoch of framelessness. However, accuracy was not satisfactoryand this limitation restricted its clinical application. Since 1990, with the development of imaging techniquesand computer science, more and more new methods such as image guidance, multileaf collimators, dynamicfield shaping, image fusion, scanning beam techniques, and inverse treatment planning systems have beenapplied in clinical practice. The first revolutionary Cyberknife radiosurgery system was used in the clinic in1994. A compact, lightweight linear accelerator is always aimed toward the target as it moves along differenttrajectories around the patient via a computer-driven robotic arm with six degrees of freedom. It continuouslymonitors and corrects for changes in patient position and motion by comparing pretreatment CT-based digitally reconstructed radiographs to digital radiographs acquired throughout the radiosurgical treatment. The Cyberknife received FDA approval to be used throughout the body in 2001, and now it is widely used all over theworld where it provides fantastic clinical results. We have summarized the general history of radiosurgery andhave introduced the working principle and clinical application of the Cyberknife.