As stated by the customary hypothesis, the cerebrospinal fluid (CSF) is secreted inside the brain ventricles and flows unidirectional along subarachnoid spaces to be absorbed into venous sinuses across arachnoid villi and via paraneural sheaths of nerves into lymphatics. Diffusion across the arachnoid granulations one-way valves into the superior sagittal sinus returns CSF to the venous circulation. Absorption of CSF into venous sinuses across arachnoid villi under the physiological pressure is considered here by means of considering fluid motion and solid response of arachnoid villi to them. A Fluid-Solid Interaction (FSI) model is constructed to simulate CSF flow. A comparison of the results and the experimental data was done. The previous rigid models have ignored the CFS interaction with arachnoid villi. In this computational fluid dynamic (CFD) analysis, the CSF pressure and flow velocity in different areas were concordant with the experimental data.