Objective To investigate the suboccipitalretrosigmoid approach-related anatomy for cranial nerve microvascular decompression, so as to provide clinical anatomical data for microvascular decompression. Methods Eight adult cadaveric heads were fixed in 10% formalin and purfused with emulsion, and then were used to simulate the operation approach. Dissections were performed gradually; the anatomy variations and neurovascular travelling, especially the upper/middle/lower neurovascular complex in cerebellopontine angle (CPA) region, were observed and measured. Results The distance between the site of trigeminal nerve going into the brain stem to the meeting point of the transverse and sigmoid sinuses was (4.4±0.2) cm; the distance between facial nerve going out of the brain stem to the meeting point of the transverse and sigmoid sinuses was (4.1±0.2) cm. The distance from midpoint of horizontal fissure of the cerebellum to anterior bone wall (the width of the CPA cistern) was (0.2±0.1) cm and the height of flocculus was (0.3±0.1) cm. Conclusion It is of great significance for clinical surgery to, via the suboccipitalretrosigmoid approach, dissect the neurovascular tissues in CPA, with focus on the relationship between important neural and vascular tissues, including the bone window, petrosal veins, and the upper/middle/lower neurovascular complex.