This study was carried out during the 2019 and 2020 seasons at the Agricultural Research Station of Al- Marashda to study the effect of three types of growing media and four levels of NPK fertilization on the growth characteristics and chemical composition of the seedlings of Inga edulis trees. The experiment comprised four NPK treatments; 0 (control), 1.5, 3, and 4.5g NPK/ pot. The applied growing media; sand, clay, and sand: clay (1:1 v/v). It was set in a split-plot design with four replicates; each contained four plastic pots. The main plot included the three growing media, the sub-plot included the four mineral fertilization treatments; to give 12 treatments. It’s obvious that planting of I. edulis seedlings in the sand: clay growing medium resulted in the highest values of growth parameters. Regarding the effects of the used treatments on the leaf content of nitrogen, phosphorous, potassium, chlorophyll a & b, phenols, and flavonoids, it is clear that growing seedlings in the sand: clay mixture; with 4.5 g/ pot of NPK fertilization gives the highest values of these components. It can be concluded that to obtain vigorous seedlings with a high content of nutrients, phenols, and flavonoids of Inga edulis, they should be grown in a mixture of sand and clay (1: 1 v/v) with monthly fertilizing by 4.5 g/ pot of NPK.