The understanding of contribution of each exposure pathway to the total internal dose is important to get the properties of health risk for volatile organic compounds and to plan a methodology of exposure reduction. This study applied 2-compartment house model to simulate the indoor air pollution of volatile organic compounds from groundwater and calculated the internal doses investigating their transfer efficiencies. For ingestion dose, the conventional method was used and compared with inhalation dose for its relative contribution and the relationship between both exposure pathways was examined. Additionally changing water volume consumed in each activity, their contribution change was observed and compared for man and woman's exposure scenarios. The results obtained from this study would help to plan for the reduction of the health risk associated with the contaminated groundwater by various organic compounds.