Cancer disparities are often considered as certain groups of people bear a disproportionate burden of cancer compared with other groups in the context of race, disability, gender, geographic location, income, education, and other characteristics. Geographic Information Systems (GIS) technology has been widely used in cancer disparities research, and help researchers visualize spatial patterns and unveil relations between health conditions, cancers, and contextual factors. This research investigated the unique needs for geovisualizaiton of cancer disparities through literature review, evaluation of web-based health mapping prototypes, and a user- centered design (UCD) approach for prototype development. A web-based cancer disparities geovisualization application was created using R shiny, an R package that makes it easy to build interactive web apps. The prototype evaluation results were analyzed using a SWOT (Strengths, Weaknesses, Opportunities and Threats) analysis framework. Most health professionals have limited GIS knowledge and experiences. In order to visualize cancer data and its contextual factors effectively, Web GIS developers should fully consider target users’ knowledge backgrounds and their research goal, such as carrying out preventative measures and plan intervention approaches for cancer disparities. We found that “dynamic user inputs”, “side-by-side synchronous interactive maps”, “easy-to-use analysis (summary, correlation, spatial autocorrelation) functions” and “intuitive tutorial” are essential features needed for web-based geovisualization tools. The five-stage user-centered design framework can provide an effective road map for guiding the development of Web GIS application, involving with target users and considering their research needs.