Wildfires pose serious threats to the society and environment. Simulation of wildfire spread and fire suppression remains a challenging task due to the complexity of wildfire behavior and fire suppression tactics. In previous work, a wildfire spread and suppression simulation model called DEVS-FIRE has been developed. Based on that model, this thesis develops a graphic user interface to support an interactive simulation environment for surface wildfire spread and suppression simulation. The developed environment allows users to dynamically set up fire spread simulations, and to interacticaly deploy firefighting agents to experiment different fire suppression tactics. This graphic user interface is implemented using the Java Swing framework, and is intergrated with the DEVS-FIRE model in a well-designed manner. The software architecture is described and the simulation environment and experiment results with different fuel, terrain and weather data are presented.