The objective of this work is to reduce the quantity of water applied by irrigation, increase the water use efficiency and determine the appropriate period for irrigation snap bean, a field experiment was implemented at the Experimental Station of Vegetable Research Department, Horticulture Research Institute, Agriculture Research Center, Giza Governorate, during the two growing summer seasons of 2016 and 2017. This study involved three irrigation intervals (2, 4 and 8 days) under clay loam soil using drip irrigation system, with spraying the plants by five antitranspirant substances (control, kaolin at 3 g/L, MgCo3 at 3 g/L, liquid paraffin 2% and bentonite 2%), The results showed that increasing irrigation intervals from 2 days to 8 days decreased the total water content in the leaves, the rate of relative transpiration, whereas caused an increase in the leaf water deficit. While, reducing the irrigation interval from 8 days to 2 days led to a significant increase in vegetative growth parameters i.e. plant height, number of branches, number of leaves, leaf area and plant weight, but dry matter percent was decreased. The yield and pods quality of the plants irrigated every 2 days showed higher values and best quality than the other periods of irrigation, the highest values of N,P and K content in the pods and chlorophyll in the leaves were found with irrigation every 2 days. Spraying snap bean plants with MgCO3 followed by spraying with kaolin led to the highest total water content, the lowest relative transpiration and the lowest leaf water deficit. The best growth characters, yield and pods quality, N, P and K concentrations and chlorophyll content were obtained from the plants sprayed by MgCO3 followed by spraying with kaolin. On the other hand, the interactions treatments between irrigation intervals and antitranspirants resulted in a significant effect in many studied parameters whereas, the superior treatment for obtained strong vegetative growth, high pods yield with best quality was the interactions between irrigation every 2days and spraying the plants with MgCo3 at 3g/L three times, the first one at vegetative growth stage (at 3-4 true leaf stage) and the others after two weeks interval of the first one.