When xenon gas dissolves into water, a hydrophobic hydration occurs and the structured water will be formed. The structured water means a large number of hydrogen-bonded water molecules which is a factor determining the viscosity of water. As the viscosity of water governs a biochemical reaction rate, the metabolism of cut flowers is expected to be suppressed when the intracellular water becomes structured. Two groups of cut carnations were placed in airtight containers of 2.124L. The one, which was control, was filled with air of 25kPa and nitrogten of 76kPa and the other was filled with air of 25kPa and xenon of 76kPa. Carnations were kept in each gas condition for 2 weeks at 293K, then both containers were ventilated to be filled with air and were kept for 1 week at 293K. Before storage, CO₂ concentration in containers of both groups of carnations under air condition were measured and normal respiration rates were calculated. They were 339mgCO₂/kg/h for carnations to be treated by xenon and 432mgCO₂/kg/h for those of the control. Respiration rates decreased and after 16 days, they were estimated as 63mgCO₂/kg/h for carnations treated by xenon and 206mgCO₂/kg/h for carnations of the control. This showed that the respiration rate of carnations treated by xenon was evidently suppressed. From visual inspection, carnations of the control deteriorated in 14 days, whereas carnations treated by xenon didn't deteriarate for 20 days.