The present investigation was carried out at the Agricultural Scientific Research Center in Swieda to study the effect of deficit irrigation on the growth of four apple seedlings rootstocks genotypes and to estimate their ability to drought tolerance particularly in light of the lack of water sources and no rain. Two irrigation levels: 100% (control) and 75% of water requirements were applied. The shoot length, leaves number, leaves area, the distribution of the roots in soil, the depth of irrigation water in the soil and the consumption of water in each level were measured. Results showed that irrigation with 75% of field capacity on studied genotypes caused reduction of shoots length, decline of leaves number and area and the depth of root comparing with the control. There were significant differences between studied genotypes in terms of vigor where the genotypes C and S2 were superior than A and B.