One-month old,rooted semi-hardwood cutting plants of pepino(Solanum muricatum Ait.) cv."Xotus" in sand-potted culture were treated by 200 mL Hoagland nutrient solution with or without additional 25 mg·L^-1 NaCl twice a week for 2 months,and exposed to(350±10),(700±10) or(1 050±10)×10^-6 atmospheric CO₂ in controlled environment chambers during the last month of the experiment,respectively.Dry mass production and water consumption of the plants decreased with NaCl salinity in the root medium,but increased with atmospheric CO₂ enrichment.Salinity raised the leaf transpiration index,root/shoot ratio,and relative distributions of dry mass into stems and roots,while reduced dry mass accumulation in other organs,water-uptake efficiency of the roots,and water consumption of the plants.High CO₂ concentrations,however,accelerated foliage development,increased total leaf area,specific leaf weight,daily increment of dry mass in plant organs and dry mass allocation to both aboveground and underground organs,accompanied by an increased dry mass-production efficiency,total water consumption and water-use efficiency of the plants.Total dry mass increment and water-use efficiency of the plants decreased by 50%—54% and 24%—37% due to salinity in the rhizosphere,but increased by 79%—106% and 61%—88% at 700×10^-6 CO₂,and by 133%—189% and 99%—142% at 1 050×10^-6 CO₂ in comparison with the 350×10^-6 CO₂ treatment,accordingly.Atmospheric CO₂ enrichment tended to improve dry mass productivity of NaCl-stressed plants by improving water-use efficiency of the plants.There were interactive effects of the combined NaCl salinity and CO₂ enrichment treatments on dry mass production and water consumption of the plants.Combined environmental conditions of rhizospheric NaCl salinity and atmospheric CO₂ enrichment promoted daily increment and relative distribution of leaf dry mass,dry mass-production efficiency and water-use efficiency of the plants,reduced total leaf area,shoot and root dry weight,water consumption of the plants,water-uptake efficiency of the roots and leaf transpiration index of the plants,correspondingly.Therefore,the global atmospheric CO₂ enrichment will be of benefit for dry mass production and water utilization of this crop.