Abstract: Objective　To observe the anatomic characteristics of pineal region and its adjacent structures by simulating midline and paramedian SCIT approach under neuroendoscopy, so as to provide anatomic basis for endoscopic treatment of lesions in this area.　Methods　Five adult cadaveric heads fixed with formalin were selected to simulate the midline and paramedian SCIT approachs under neuroendoscopy. The structure of pineal region was observed and measured, and the exposure of the two surgical approaches was compared.　Results　The distance from the dura mater midline and paramedian SCIT approachs under neuroendoscopy to the cerebellar fissure vein were (58.14±1.62) mm and (76.51±2.25) mm, and the relative degree of freedom were (0.09±0.01), (0.05±0.01). The relative degrees of freedom of pineal gland were (0.47±0.01) and (0.35±0.09), and the relative degrees of freedom of superior colliculus were (0.26±0.05) and (0.40±0.07). The left and right operable angles of the pineal gland were (14.85±0.35) and (17.86±1.03) degrees, respectively, and the anterior and posterior angles were (21.40±1.41) and (15.00±3.06) degrees. The left and right operable angles of the corpus callosum were (14.55±0.07) and (17.04±1.57) degrees, and the anterior and posterior angles were (14.60±0.71) and (18.76±2.83) degrees. The left and right operable angles of the ipsilateral superior colliculus were (15.63±5.08) and (21.62±2.19) degrees, and the anterior and posterior angles were (11.18±4.72) and (18.94±4.08) degrees. There were statistical difference between them (P<0.05).　Conclusions　Midline SCIT approach and paramedian SCIT approach have their own advantages. The surgical approach should be selected according to the specific location of the lesion. 

Key words: Neuroendoscopy, 　Pineal region;　 Surgical approach;　 Anatomy