The present study was conducted to investigate the accumulation of heavy metals into crop plant (lettuce and barley) and the behaviors of heavy metals in soil after irrigation of domestic wastewater. The levels of heavy metals in domestic wastewater were 10 to 100 times higher than those in the ground water (trace levels or not detected). The application of domestic wastewater to farmland has significantly increased the levels of Pb, Cd, Cu, and Zn in soil. The concentrations of heavy metals in crop plant grown in the domestic wastewater-irrigated soils were significantly higher than the contents found in the ground water-irrigated soils, thus indicating that the application of domestic wastewater had enriched the soils with heavy metals. Furthermore, continuous monitoring and pollution control of hazardous materials is needed in order to achieve sustainable crop production.