To study CSF dynamics and brain functional activity simultaneously with quantitative aspect, we proposed a new method for quantifying CSF pulsatility information based on an interslice CSF pulsation model in 4th ventricle of EPI-based fMRI (CSFpulse). The proposed CSFpulse successfully detected the higher CSF flow during the resting state than the typical task states, both in quantitative and time course aspects. Also, CSFpulse was significantly correlated with stroke volume measured using phase contrast MRI during functional states. Based on these results, CSFpulse can be used for investigating functional changes in BOLD and CSF pulsation simultaneously based on conventional EPI-based fMRI.