Based on many studies and experiments, blood flow patterns are associated with cardiovascular diseases and it usually is a sign of cardiovascular disease when the blood flow becomes unusual. Magnetic resonance (MR) imaging is a non-invasive medical technique and the characteristic of phase contrast can use to measure the flow velocity and patterns in vivo. As far as we know, for the cardiovascular of region of interest, 4D Flow-sensitive MRI technology is good at spatial coverage and temporal resolutions.It is easier for the researcher to analyze blood flow patterns in the clinical diagnosis by visualization processing. EnSight (CEI, USA), a kind of commercial software, is often used to do visualization processing of data of 4D Flow-sensitive MRI. However, before visualization of the data, several actions must be completed, such as ROI selection, correction or conversion of data, and etc. Therefore, our thesis hopes to develop a simple but practical user interface tool for 4D Flow-sensitive MRI data. From reading the file and ROI selection to correction and conversion of data as well as the visualization processing are completed by this tool. It provides researchers a rapid examination of data and analysis of blood flow patterns in the diagnosis.