Abstract: Vigor reduction of cherry varieties by dwarfing rootstocks is well known, but the mechanism by which a rootstock induces dwarfing is not well understood. Phenolic compounds have been associated with dwarfing mechanism. However, the role of these compounds in mahaleb dwarfing mechanism is not definitive. Quantifying the phenolic content in mahaleb genotypes is the first step in understanding their role in dwarfing mechanisim. This study was conducted at Khorasan Natural Resources and Agricultural Research Center on 30 dwarf selected mahaleb genotypes possessing different degrees of vigor to determine, the relation between vigor, total phenolic content and mineral nutrition. There were significant differences in leaf and stem bark phenolic content among genotypes. The ranges of variation for stem bark and leaf total phenol content were 185.6, 165.50 in selected dwarf mahaleb genotypes and 43.25, 55.94 (mg CAT/g dw) for high vigor genotypes respectively. We found that there was a direct relationship between vigor and total phenol content. The highest N, P and K element concentrations were found to be high vigor genotypes. Correlation coefficient showed significant correlation between tree vigor with leaf total phenolic content (R2 = -0.586), stem bark total phenolic content (R2 = -0.690), nitrogen (R2 = 0.549), phosphorous (R2 = 0.512) and potassium (R2 = 0.453). We conclude that total phenolic content and some mineral nutrition can be used as a criterion for prediction vigor.