In this study, the finite difference modeling technique is used to develop a simulation program that can be used for groundwater contamination problems. The simulation program is written in C++ programming language and runs on personal computers using Windows 95. The simulation program supplies an interactive user interface containing useful tools for pre-processing and postprocessing the data. Numerical models are capable of simulating two-dimensional areal aquifer systems with various conditions. Finite difference equations are derived by using vector volumes. Groundwater flow equations and advective-dispersive contaminant transport equations are solved in an uncoupled method. The iterative alternating direction implicit method is used with the Gauss elimination method to obtain solutions. Solution codes for the flow equation are implemented from previous researchers ' studies in this field. Variable grid generation is added to the implemented codes. The program is capable of displaying head and concentration distributions and velocity fields on the discretized aquifer domain. It is supplied with various output file options for the solutions.