The aim of this study is to determine the effect of different doses of leonardite application on water-yield relationships of Amaranth plant. The research was carried out as a pot trial in Kahramanmaraş Sütçü İmam University Faculty of Agriculture research areas. In the study, 5 different leonardite treatment (L2, L3, L4, L5, L6) were arranged according to 18 repeats, one plant per pot. The study, which was arranged according to the randomized plot design, was carried out with 90 pots. Soil water status was determined by Time Domain Reflectometry (TDR). During the growing period, 75.64-82.99 L water was given to the plants. While the water use efficiency (WUE) was between 0.28 and 0.63, g L^-1 the irrigation water efficiency (IWUE) was between 0.40 and 0.97 g L^-1. The plant-yield response factor was 1.54.According to the results obtained from the study, the highest yield, thousand kernel weight, plant height and panicle height value were found as 72.41 g number^-1, 0.75 g, 92.66 cm and 21.66 cm from L6 treatment, respectively. The lowest yield, thousand kernel weight, plant height and panicle length were 29.94 g number^-1 for L3, 0.54 g for L4, 72.5 cm for L2 and 13 cm for L2, respectively.