Abstract: Objective: To investigate the morphologic relationship between the precentral sulcus(PreCS) and its adjacent sulcus on the axial and sagittal MRI of the brain.Methods: The continuous axial and sagittal MRI based on AC-PC line in 30 normal adult heads were obtained to identify,localize and classify the cerebral PreCS using the eFilm Workstation 2.1 and Adobe Photoshop 8.0 software in the microcomputer.The morphologic relationship between the PreCS and its adjacent sulcus were studied.Results: The PreCS intersected the cerebral longitudinal fissure in the shape of "Y",and the detection rate of MRI was 8.33%;the PreCS intersected the superior frontal sulcus,the middle frontal sulcus and the inferior frontal sulcus in the shape of inverted "Y",and the detection rates of MRI were 90.00%,3.33%,and 76.67%,respectively;the PreCS was not only parallel to the central sulcus,but also intersected the CS,and the detection rates of MRI were 83.33% and 16.67%,respectively;the PreCS intersected the lateral fissure in the shape of inclined "Y",and the detection rate of MRI was 80.00%;the PreCS was parallel to the anterior ascending ramus of lateral fissure,and the detection rate of MRI was 98.33%.Conclusions: The results may provide sectional-imaging anatomical basis for the level diagnosis,stereotactic and minimally invasive neurosurgery in the PreCS neighboring areas.