목적: To provide simultaneously reconstructed virtual reality integrated with microscopic visual field. 방법:New navigation system was developed which can provide the augmented virtual reality between CT images and operating microscope. The virtual reality includes superimposed CT sections on the microscopic visual field (simultaneously reconstructed according to the visual field and scrolled along the axis) and three-dimensionally reconstructed image. The system was validated on temporal bones for its measuring accuracy, imaging quality and convenience for use 결과:The system successfully superimposed underneath critical structures (i.e. facial nerve, cochlea) on the microscopic visual field for middle ear surgery and indicated the distances to those structures. The system also superimposed hidden anatomical landmarks (i.e. IAC, facial nerve, superior canal in middle fossa approach) or target structures (i.e. endolymphatic sac) for surgeries with vague anatomical landmarks. All structures were confirmed by guided actual dissection and the measurement error was reduced to less than 1.0 mm. 결론:The present system could successfully provide reliable anatomical information adjusted to diversely changing microscopic visual field. It seems to be useful in surgeries for anomalous structures or without clear anatomical landmarks.