This study was carried out in Desert Research Center and Zagazig Univ., Egypt under , North Sinai conditions during three growing seasons, i.e., summer 2018, fall 2018/2019 and summer 2019 to assess the effect of radiation mutants on leaf histological features and genetic stability of the productivity of some potato cultivars under drought stress conditions. Results reveal that the genotypes can be divided to four categories (with low in S2di are considered in all categories) as following: i) Genotype with high mean, bi=1, it is considered as stable genotype where Cara cultivar (both generations) was included. ii) Genotype with high mean, bi>1 as genotype with average stability where Spunta cultivar was included. iii) Genotype with low mean, bi< 1 as genotype with low stability where Hermes (both M1 and M2 generations) and Caruso (2nd generation) cultivars were included. iv) Genotypes with a few bi values in one generation, as genotype with low stability but are not recommended for use in this generation where Caruso cv in M1 was included. It is evident that Hermes could be used as stress tolerant genotypes under stressed environments (poor yielding or unfavorable environments). However, Spunta followed by Cara cv presented a high performance in M2 yield production (10.97 and 8.51 ton/fed, respectively), low deviation from the regression line and the regression coefficient nearby 1, so that both cultivars were superior among genotypes in terms of yield stability and recommendable for all environments. According to anatomical studies, 80 % from field capacity (FC) decreased the thickness of medvein and lamina of potato cv. spunta and herms plants and thickness of mesophyll tissues as well as dimensions of medvein bundle and mean diameter of vessels. Plants treated with gamma ray at level 20 and grown under 80 % FC induced prominent increase in all previous characters.