This study was carried out to evaluate the effect of spray by boron at different concentrations (0, 10, 20, 30, 40, 50 ppm) for one time (60 days after transplanting, DAT) or two times (60 and 90 DAT) on sweet potato plant, Abees cv. The experiment was conducted at Kafr El-Sheikh governorate that counted the main growing area in Egypt, under clay soil conditions. The results indicated that repeat spraying of B at 60 and 90 DAT by the concentration of 40 or 50 ppm increased vegetative growth parameters (plant length, number of branches and plant leaf area) and growth attributes (leaf area index, absolute growth rate and net assimilation rate). Also, morphological quality of the tuberous root (diameter, length and shape index) as well as yield with high average of marketable yield percentage were improved.