Abiotic stress such as salinity is an important factor that limits plant growth and performance. Information regarding the genotypic variation for salinity stress tolerance in sweet cherry rootstocks is limited. In this study, salinity tolerance mechanisms of three sweet cherry rootstocks, namely; Colt (Prunus avium x Prunus pseudocerasus), Gisela 5 (Prunus cerasus x Prunus avium) and Maxma (Prunus mahaleb x Prunus avium), grown widely in Turkey were investigated under in vitro condition. The three rootstocks were cultured in vitro on MS medium supplemented with 0, 25 and 50 mM sodium chloride (NaCl). The Shoot growth, lipid peroxidation (MDA), membrane permeability (MP), total antioxidant activity (TAA), proline, total chlorophyll contents, catalase (CAT, EC 220.127.116.11) and peroxidase (POD, EC 18.104.22.168) antioxidant enzyme isoforms of rootstocks were studied. Compared to the control, salinity resulted in a reduction in the shoot growth and total chlorophyll contents. Contrary to this, MDA contents, MP, TAA and proline contents were increased by salinity. Activity of POD in the shoot of rootstocks was increased and three different POD isoforms were exhibited under saline conditions. The activity of POD was lower in the Maxma than the Colt and Gisela 5 rootstock. Salinity did not significantly change the CAT isoforms of the rootstocks. Regarding the all parameters studied, the rootstocks can be classified to their salt tolerance as sensitive (Maxma), moderately sensitive (Colt) and resistant (Gisela 5).