In order to investigate the effect of deficit water stress and different combinations of relay intercropping of chickpea with barley on some biochemical traits and grain yield, a field experiment was conducted at College of Agriculture and Natural Resources of Darab, Shiraz University during 2017-2018 cropping season, as split plot based on a randomized complete block design with three replications. Treatments included two irrigation regimes (normal irrigation and cutting off irrigation at milk development stage) as main factor and the 6 combinations of cropping systems consisted of cultivation of barley on December, barley on January, and different combinations of intercropping consisted of barley in December + chickpea in December, barley in December + chickpea in January, barley in January + chickpea in December, and barley in January + chickpea in January with a ratio of 1:1 as sub factor. Results showed that deficit water stress had significant effects on chlorophyll a, catalase and peroxidase activity, leaf relative water content (RWC) and contribution of current photoassimilates to the grain yield of barley and grain yield of chickpea. Under deficit water stress, barley grain yield had a positive correlation with leaf relative water content (R2=0.47)*. Also, under deficit water stress condition, the highest carotenoid content was obtained from intercropping of barley in December + chickpea in January. Since intercropping of barley in December + chickpea in January had the highest carotenoid content, remobilization efficiency, and contribution of current photoassimilates to the grain yield of barley and hence grain yield of barley (4215.7 kg/ha), it may be a suitable cultural strategy to be taken under late season deficit water stress conditions.