The objective of this work was to evaluate the effect of water stress caused by the reduction of soil water availability on root development and the commercial characteristics of carrot grow crops Nantes and Brasília Calibrated Average in protected environment. The study was conducted in a greenhouse at the State University of Goiás, Câmpus Ipameri. Sowing was carried out in July 2016, and the experimental design was a randomized block design, analyzed in a 2 x 5 factorial scheme with four replications. The treatments were composed of the cultivars (Brasília Calibrated Average and Nantes) x percentage of available water in the soil (20, 40, 60, 80 and 100%). The fresh and dried masses of the individual parts of the plants (root, leaf), length, diameter, commercial classification, yield and root defect were determined. The data obtained were treated with statistical analysis through the F test and when significant regression analysis was applied. Regarding the development, the carrot Nantes of carrot in protected environment the blade of 70% obtained the best data. For the cultivar Brasília Calibrada Average the slides between 70% and 80% presented satisfactory performance for the evaluated parameters. The cultivar Brasília Calibrada Meio, showed a higher percentage of increment for regression. For the commercial classification, size and absence of defect, the Nantes cultivar in the 40% blade was the one that presented the best.