This study was conducted to investigate the physiological and structural damages to cadmium (Cd) in Acorus calamus var. angustatus as a native aquatic species in Korea. In addition to the physiological responses such as plant growth, photosynthesis, and root activity, the structural damages in leaf and root tissues were observed through light and scanning electronic microscopy. The five-leaf plants were treated with different Cd concentrations 0, 10, 25, and 50 ${mu}M$ for 15 days. The plant damages to Cd were significant at 10-25 ${mu}M$ Cd physiologically and at 25-50 ${mu}M$ Cd structurally. The physiological damages in the shoot part (photosynthesis) started at 10 ${mu}M$ Cd whereas those in root part (root activity) were serious above 25 ${mu}M$ Cd. On the other hand, the structural damages began at 25 ${mu}M$ Cd in the leaf and root tissues similarly, but the plant tissue destruction was more serious in the roots than in leaves. Based on the plant physiological and structural damages, 10 ${mu}M$ was assumed to be the limited concentration for sustainable growth and landscaping ability in Acorus calamus var. angustatus to Cd.