There have been many challenges for plant science researchers to overcome the difficulties associated with soil, climate and environmental sucessful conditions, in order to improve crops quality, yields and productivity. The present study aimed to provide new insights into alfalfa germplasm in order to improve tolerance to arid conditions, along with high yield potential and forage quality. We compared the effect of harvesting time on forage yield and nutritional quality of eight alfalfa genotypes of different origins (native, selected and introduced). The results showed significant (p<0.05) genetic variability among the genotypes for the agro-morphological traits; dry matter yield, total plant height, number- and length of internodes at different harvesting times. Besides, harvesting at different phenological stages determined the biochemical composition in dry matter, ash, crude proteins, total soluble proteins and sugars and free amino acids. Our results, based on the multivariate cluster analysis and principal component analysis (PCA)-biplot may suggest the genotypes of alfalfa well adapted to stressful environments outside oasis of arid regions. This may bring insights into their use in culture or in breeding programs in attempt to improve adaptability of alfalfa crops to environmental arid conditions.