Abstract: The effect of application β-Aminobutyric Acid (BABA) on Crimson Seedless grape vine was studied in 2012 and 2013 seasons, as an alternative to traditional chemical compounds that are harmful to the environment to control the pre and postharvest diseases. The vines were sprayed with three levels of BABA (200, 250, 300 ppm) two weeks before harvest. The linear growth and dry weight of Botrytis cinerea isolated from Crimson Seedless grape were greatly influenced by the increase in BABA concentration up to 300 ppm. In both seasons, prolonging the marketing stage resulted in decreased in disease infection with the increase in concentrations, at 300 ppm concentration, BABA gave the maximum reduction in disease infection caused by Botrytis cinerea, in addition to the improvement of fruit quality at harvest and during cold storage (for 60 days at 0±1°C with 90-95% RH), as well as 3 days marketing period at room temperature. Clusters treated with 300 ppm BABA developed less decay shatter and total loss. Moreover, it was more effective in rising SSC, titratable acidity, total sugar and anthocyanin accumulation in the skin of berry during cold storage conditions and marketing period compared with the other treatments. While, BABA 250 ppm showed high berry firmness and adherence strength.