Abstract: To harvest and compost water hyacinth and then use it as a component of the medium in soilless culture is a novel train of thought to turn waste into resource. However, as the wastewater from aquacultural farms generally contains heavy metal pollutants, like Cu, and so does the plant growing in the wastewater, it is necessity to assess impacts of the culture media contain in composted water hyacinth on growth and food safety of the vegetable in soilless culture. Results show that in media with Cu varying in the range of 0-600 mg·kg^-1 growth of radish and water spinach were not significantly affected, and Cu concentrations in the edible parts of the two vegetables were within the safety limits (10.0 mg·kg^-1) set in the National Standard for Food Safety of China, but a relatively higher Cu concentration, about 15 mg·kg^-1, in roots of the water spinach was detected. The concentration of Cu was significantly lower in the edible parts of radish (0.2-1.6 mg·kg^-1) than in those of water spinach (0.5-4 mg·kg^-1). The content of Cu in the plants was found to be significantly related to the content of exchangeable Cu in the growing media. So it is much safer to plant radish than water spinach in soilless culture using composted water hyacinth in the medium. It is, therefore, essential to consider not only content and availability of Cu in the soilless culture medium, but also species of the vegetable to plant and characteristics of their biological Cu absorption in assessing potential risk of heavy metal pollution of the culture medium to food safety.