To identify the responses of enzymatic and non-enzymatic antioxidant activities in response to yield the study was undertaken in different Brassica juncea cultivars such as Pusa Bold, RSPR-01, RSPR-03, Kranti and NRCDR-2 under drought stress conditions at 45, 60 and 90 days respectively, days after sowing (DAS). The study was done in the Division of Plant Physiology, Chatha, SKUAST, Jammu during Rabi 2016-17, a pot experiment was conducted with factorial completely randomized design with three replications. Parameter such as relative water content in leaves, relative stress injury, antioxidant enzymatic activity, proline content, number of seeds per pod, number of pods per plant, 100 seed weight and seed yield were also studied. To determine the relative tolerance of genotypes, the drought susceptibility index (DSI) for seed yield and its attributes were recorded. The activities of enzymatic antioxidant such as superoxide dismutase (SOD), peroxidase (POX) and non-enzymatic antioxidant ascorbic acid preferentially enhanced by the drought stress. Relative water content, dry weight decreased, whereas relative stress injury, proline content increases with the increase in the drought stress given at various days after sowing. At flowering stage reduction in seed yield was observed when drought stress imposed and it also affects silique development. It was noticed that reduction in seed weight was minimum when drought stress was induced before flowering. These results indicate that protection from oxidative damage by higher levels of antioxidants may be involved in the development of drought tolerance in Brassica juncea. These biochemical parameters results can be used as practical for selection of drought tolerant brassica juncea genotypes when selecting drought tolerant cultivars for breeding in arid regions.