Abstract: The objective of this study was to investigate the sensitivity of morphological and physiological responses of burr medic (Medicago polymorpha L. cv. Scimitar) and balansa clover (Trifolium michelianum L. cv. Frontier) to low levels of salinity. Morphological responses determined included leaf width, leaf length, plant height and dry matter yield. The results indicated that sodium (Na+) and potassium (K+) content in both leaves and stem tissues increased with increased salt levels. Sodium contents in leaves under 80 mM salt levels were 3-fold and 2-fold than for the control for balansa clover and burr medic, respectively. Leaf Na+/K+ ratio remained relatively constant in both balansa clover (0.3-0.4) and burr medic (0.4-0.5). Stem Na+/K+ ratios ranged between 0.3-0.7 in balansa clover and between 0.4-1.0 for burr medic. These results indicate that burr medic is much more high-yielding and seem to tolerate the levels of salinity just as well as balansa clover.