Biodegradation process is an economical and effective way to degrade organic chemicals in remediation sites-Based on the intensity study about chemical s degradation processes, a comprehensive mathematical model, which describes chemicals diffusion, sorption/desorption, sequestration, and biodegradation in soil-water-microbes system, has been developed in this paper-A sensitivity analysis was performed to assess the effect of several parameters on model behavior-It is noteworthy that the chemical s concentrations in soil, in particle water phase, in bulk water, as well as the necessary remediation time can be predicted by using this model.