Twenty grain sorghum genotypes of different geographic origin were evaluated in three locations (Shandaweel Agricultural Research Station, Sohag governorate; ElKharga Agricultural Research Station, New valley governorate and Abo-Sombel Agricultural Research Station, Toshqi) in the summer season 2019 for assessment of the variability among the genotypes, correlation coefficient and drawing the phylogenetic tree using cluster analysis. The results indicated highly significant differences among the genotypes, environments and their interaction for all traits under investigation, suggesting that these genotypes were highly variable for almost all traits, therefore, would respond to selection. The Egyptian genotype (Dorado x LC) gave the best performance for most of studied traits under each environment and their combined data. This genotype could be released as a new Egyptian grain sorghum variety after testing in a large scale. The individual and the combined analyses indicated that most genotypes had higher genotypic and phenotypic variance components than the environmental variance, which an indicative that the environment had less effect on the expression of the studied traits; for that is these genotypes may be exploited in breeding programs. The traits which showed high genetic advance as a percentage of mean (Δg %) were plant height, panicle length, panicle width, 1000- grain weight and grain yield/plant. Moderate GCV% and PCV% were also observed for all studied traits except days to 50% flowering and number of green leaves, revealing that the genotypes have a broad base genetic background as well as good potential that will respond positively to selection. The correlation between grain yield/plant and the other studied traits was negative and highly significant for days to 50% flowering and positive and highly significant with the rest of studied traits, which mean that any improving in these traits will directly give improvement in grain yield. The lowest similarity (87.00%) was observed between genotype 5 (ICSR 89016) and genotype 15 (Dorado x LC) which are located in different groups and was located in highly diverged clusters, Therefore these genotypes were found to be a good parents for a hybridization or heterosis breading programs.