Purpose: A comprehensive quality assurance program has been established in Beijing hospital to ensure that "radiosurgery" be carried out precisely and safetely.Materials and Methods: A film checking technique was used to verify the localization accuracy and the setting-up accuracy.Results: The figures taken from 80 cases treated show that the setting-up accuracy of the target positions be within ?1mm .Conclusion: The positional accura cies during target localization and setting-up are guaranteed by using our QA procedures.