The possibility of using phase modulation spectrophotometry for the detection and recognition of large blood vessels and nerves in the biological tissues volume in the tasks of neurosurgery with endoscopic endonasal access while removing the skull base tumors has been investigated. Optical and dynamic characteristics of various neurovascular structures types were studied. Informative independent parameters and their corresponding criteria for the detection and recognition of neurovascular structures in the tissue volume, based on the difference in the optical properties of the blood, nerves and their surrounding tissues, was proposed and experimentally investigated in vivo and in situ. The obtained preliminary results indicate the promise of applying the method of phase modulation spectrophotometry in endoscopic neurosurgery and can be used in spectrophotometry with the impulse time-domain approach.