Abstract: The experiment was conducted in four cemented tanks of four guar genotypes i.e. S-807, Esser, Brooks and S-1183, under different water regimes (control, pre-post flowering stress, and terminal stress). The treatments were imposed at different stages of growth. Photosynthetic efficiency was determined by measuring leaf area, chlorophyll content and seed/yield. The findings show that water deficit reduced seed yield leaf area and chlorophyll content in all four guar genotypes. However, the genotypes S-807 and Esser had comparatively better performance than the other genotypes tested i.e. Brooks and S-1183.