Saline tolerance of mango rootstocks is, or will be, of major importance in many mango growing areas. In four experiments, different, Mangifera species (M. indica L. cv. '13-1' and 'Turpentine', M. zeylanica Hooker f.) were characterized in a controlled environment. During increasing levels of NaCl salinity (15 to 120 mM) physiological description data of whole plant CO 2 gas exchange (CO2 assimilation A, dark respiration RD, root respiration RR and carbon gain cG) were simultaneously recorded over a period of up to one month. At the end of the experiments mineral composition was recorded in various plant parts. Three representative days with 24 measurements for every hour a day were selected in each experiment, snowing that low NaCl concentrations (15 and 30 mM) reduced A and RD six days after the treatments started. After 3 more days and an increase to 60 mM NaCl a significant reduction of A was measured compared to control plants. In another experiment NaCl-salinity reduced A in both rootstock cultivars without clear difference, but M. indica '13-1' had lower RR compared to M. indica 'Turpentine' and higher CG. No significant differences in mineral contents were measured, but M. indica '13-1' had absolute higher Na+, CI- and Ca2+ contents in leaves. M. indica '13-1' compared directly with M. zeylanica showed clear differences. At 60 mM NaCl A was 8 μmol CO2 m-2s-1 in M. zeylanica and only 3 μmol CO2 m-2s-1 in M. indica '13-1'. In M. zeylanica a higher RR was measured. Significant lower Na+ contents were found in roots and young leaves of M. zeylanica as compared to M. indica '13-1'. The K+ contents and K/Na ratio were significantly higher in roots of M. zeylanica. Physiological characterization of whole plant CO2 gas exchange under controlled environment conditions may be a useful tool for plant description. Data indicated only small differences in salt tolerance between M. indica '13-1' and M. indica 'Turpentine'. Promising higher tolerance may exist in M. zeylanica.