An apparatus and method for visualizing data. The apparatus for visualizing data includes a behavior information collection unit for executing an application from which information is to be collected and collecting behavior information from a process of the executed application, a behavior feature extraction unit for extracting behavior features in an order in which the behavior information is called, a behavior sequence generation unit for generating a behavior sequence by arranging the behavior features in chronological order, and a behavior sequence visualization unit for visualizing the behavior sequence as a 3D sequence object.