Abstarct: Accumulation of organic compatible compounds is a strategy that plant used to reduce the negative effects of stress. These compounds protect plant from stress by different processes, including osmotic adjustment. Sucrose is one of the osmoprotective compounds that accumulate in stress conditions. In order to examination of sucrose foliar application effects on some morphological and physiological traits in Vigna sinensis L. subjected to water deficit, an field experiment was conducted at the department of agronomy and plant breeding of Shahrood University of Technology in 2011. A spilit plot factorial experiment on the basis of completely randomized block design was carried out in three repetitions. The main factor was three irrigation levels including 8 days interval (well water), 12 days interval (moderate stress) and 16 days interval (severe stress) and sub-factors were three sucrose concentration (15, 30 and 45 g/l) and foliar application time (vegetative growth and seed filling stage). First and second foliar application performed in 36 and 56 days after sowing respectively. The results showed that water deficit stress decreased pod dry matter, leaf area index, number of pods per plant, yield, relative water content and protein yield, while stem diameter, stability of the plasma membrane and leaf soluble carbohydrates were increased. The intraction between stress and sucrose concentration was significant on all of traits except stem diameter, 1000 seed weight, number of seeds per pod, seed phosphorus and seed protein percentage. The highest leaf dry matter (136.56 g/m2) and leaf area index (1.68) was obtained from well water and 15 g/l sucrose concentration. The highest yield (0.24 Kg/m2) was obtained from well water and 45 g/l sucrose concentration, because the number of pods per plant increased in this treatment. Leaf soluble carbohydrates were increased by water deficit stress. So that 12 and 16 irrigation levels compare to 8 irrigation level increased leaf soluble carbohydrates 55.74 and 77.45% respectively. The effect of sucrose concentration on seed protein percentage was significant. The highest seed protein percentage was obtained from 45 g/l sucrose concentration that was higher than 30 and 15 g/l concentrations (0.39 and 1.52 percentages respectively). In summary, study of different treatments showed that the foliar application of sucrose with 45 g/l concentration had greater effect on the most traits in well water and severe stress coditions.