With increasing groundwater contamination, the study of contaminant transport is becoming more and more important. Since chemical reactions occur simultaneously with contaminant transfer, these two aspects should be coupled in one model. PHREEQC is a simulation software package for modeling chemically reactive transport processes in natural and underground water bodies. PHREEQC was applied to simulate the processes of cation exchange and kinetic redox transformations with 1D groundwater flow. The results show that PHREEQC can successfully simulate complex geochemical reactions coupled with steady water flow. However, for the simulation of multi-dimensional groundwater flow and contaminant transport, it is necessary to couple PHREEQC with other groundwater flow and species transport models.