Drought stress has multiple effects on the plantdevelopment. Photosynthesis is one of the key metabolic processes which determine plant productivity. The objective of present study was to understand the effects of drought stress on wheat var. [HI-1531(Harshita)] through fast chlorophyll a fluorescence analysis (OJIP). Various phenomenological parameters suggest that mild drought stress have no significant effect on the primary photochemistry of photosystem II (PSII) in var. HI-1531. The light harvesting complexes was found stable even in severe drought stress.