The aim of this study was the effect of different levels of water stress on some morphological and physiological parameters of three Iranian genotypes of apricots and comparison the tolerance of the seedlings to drought stress. Therefore, an experiment has been carried out as factorial based on completely randomized design in a controlled greenhouse with 9 treatments and 4 replications. In this study, 3 levels of drought stress including control (90% of field capacity), moderate drought stress (60% field capacity) and severe drought stress (40% field capacity) were applied on three genotypes (Abarkouh, Rabor, Sabzvar) of apricot and measurement was performed 30 days later. The results of morphological, physiological and biochemical parameters showed that these parameters have been affected by the drought stresses levels. Drought stress on seedling of apricot genotypes, reduced plant height, leaf relative water content, leaf area, chlorophyll, carotenoids, chlorophyll fluorescence and increased electrolyte leakage, proline, glycine betaine and soluble sugars compared to the control (90% FC). Due to the lowest decrease in height and leaf area, the lowest amount of ion leakage, the highest relative water content of leaves, total chlorophyll, PI and Fv / Fm, Sabzevar genotype was less affected by drought stress than the other two genotypes. Therefore it can be said that Sabzvar genotype is mor tolerant, Rabor genotype is moderate and Abarkouh genotype have less tolerance to drought stress.