A field experiment was carried out in clay soil to investigate the effects of gibberellic acid and proline, and their interaction on the vegetative characteristics of Zea mays L. cultivar Fajir-1. The experiments were carried out based on the Randomised Complete Block Design. Gibberellic acid and proline were sprayed twice on the plant leaves at the concentration of 100 and 200 mg/l. The first application was during the stage of 4-6 leaves, and the other application was at the beginning of flowering stage. The results show that the addition of gibberellic acid at the concentrations of 100 and 200 mg/l, and the proline at the concentration of 200 mg/l significantly affected the studied characteristics including: plant height, number of leaves per plant, leaf area and shoot and root fresh weights. The results also show that the interaction between gibberellic acid and proline did not show any significant effects on the studied characteristics except for the leaf area.