study was conducted on one- year old sour orange seedlings in long term experiment during 2014 and 2015, held in greenhouse of EL-Maamora station, Horticulture Research Institute. The aim of trial was to evaluate foliar chitosan or putrescine application at 0, 50, 100, 150 ppm and three levels of irrigation (7, 14 and 21 days) contributing to three levels of drought stress (zero, moderate and severe, respectively) on growth, leaf biochemical attributes and antioxidant enzymes activity. Results showed that most of the vegetative growth indices, plant height %, stem diameter %, leaves number, area, fresh and dry weight and relative water content(RWC) %,leaf carbohydrates and protein % were significantly decreased with increasing drought level and that chitosan and putrescine application resulted in enhancement gradually of the previous parameters by increasing  concentrations applied. Putrescine was more effective at 50 and 100ppm compared to 150 ppm, whereas chitosan was more effective at 100 and 150ppm than 50 ppm .