Impacts of drought on morphophysiological, biochemical and molecular changes in crops limit the performance and their yield. Its impacts include growth and development, water relations, membrane integrity, pigment content, osmotic adjustment, photosynthetic activity and harvest index. The different acclimation factors such as changes in plant structure, wax deposition, reduced growth rate, tissue osmotic potential and antioxidant defenses. Oxidative stress is common detrimental factors in drought which produce reactive oxygen species (ROS) viz. superoxide (O2-) radicals, singlet oxygen (1O2-), hydroxyl (.OH), alkoxyl (RO•), peroxyl (ROO•), lipid peroxyl (LOO•), hydrogen peroxide (H2O2), etc. that causes sequential damage of membranous structure in the cell and eventually lead to dry and decay of whole plant. The metabolites that have different types of role in metabolism play a major role in suppression of these ROS in plants. The Ascorbic acid, Glutathione, Carotenoids, Phenolics, flavonoids, alkaloids, Tocopherols, Tocotrienols, Proline, taurine, nano-silicon etc. are the major metabolite that scavenge the ROS in different metabolic pathway. The enzymatic antioxidants viz. superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase produced under drought and scavenge ROS and minimize the drought. Molecular changes during drought produce the several enzymes that catalyze the production of ROS scavenger and drought responsive metabolites. Thus internal mechanism and structural changes during drought save the crops from diurnal and long term drought.