Abstract: Objective: To observe the change of intracranial pressure(ICP) and cerebral hemodynamics of elderly patients undergoing laparoscopic gynecological surgery in modified chest-up Trendelenburg position(T position) by ultrasound. Methods: Forty ASA I-Ⅱpatients, aged ≥60 yr, weighed 44-69 kg,scheduled for elective gynecological surgery, were randomly divided into 2 groups with 20 in each. Patients of study group(group M) were placed in chest-up T position by using custom made posture cushions. And patients of control group(group T) were placed in conventional T position.The optic nerve sheath diameter(ONSD),time-average peak velocity(TAPV) of middle cerebral artery,pulse index(PI),and resistance index(RI) in supine position at 5 min after regular general anesthesia induction (T₁),and that in modified T position or T position immediately after pneumoperitoneum (T₂), 30 min later(T₃), 60 min later(T₄), 90 min later(T₅),and that in horizon position at 15 min after deflation(T₆), were measured. Results: Compared with that at T₁,the TAP and PI at T_2,3,4,5 significantly increased in both groups, the ONSD and RI at T_4,5 significantly increased in group M, and the ONSD and RI at T_3,4,5,6 and PI at T₆ significantly increased in group T(P＜0.05).Compared with that in group T, the ONSD and RI at T₃ and T₆ significantly decreased in group M, and the TAP and PI at T₂ significantly decreased in group M (P＜0.05). Conclusions: Modified chest-up T position delays the increase of ICP and cerebral blood flow(CBF),and accelerates their recovery to the normal range after deflation. It is conducive to the safety of prolonged surgery.