Effect of irrigation water salinity was investigated on both the yield and quality of sainfoin and soil salinization under greenhouse conditions in 35 cm wide and 65 cm long PVC columns. Sainfoin was chosen because it is grown in arid and semiarid region with salinity problems and it is cold resistant. 5 levels of water salinity (0.27, 3.5, 7, 10 and 13 dS m(-1)) and two levels of alkalinity (SAR= 0.35 and 10) were evaluated as a factorial in a randomized - plot design with three replicates. Sainfoin was harvested twice. Plants got shorter and dry hay yield and crude protein ratio were declined as the levels of salt and alkalinity increased for both harvests. There were no live plants in the second harvest when salt concentration and alkalinity was highest. Increase in soil salinization was also observed with increasing water salt level.