There are global concerns about the significant increase in the concentrations of heavy elements due to the increase in agricultural, urban and industrial activities, which poses a threat to the natural environment and humans. This study focused on studying the addition of humic acid and different levels of zinc on the presence of zinc in the soil in its different forms and its readiness for the plant to find the best concentration and with the presence or absence of humic acid. This study was carried out on the sunflower crop, as zinc was added at levels of (0, 15 and 30) kg h-1 and humic acid at two concentrations, (0 and 50) kg h-1. Zinc was extracted successively and total and available zinc was measured. The results indicated: Concentration of total and available Zinc associated with carbonate minerals, with oxides, and with organic matter in soil increased with increasing levels of Zinc added to soil, reaching 8.638, 1.049, 1.971, 1.658 and 1.625 mg kg-1 soil, respectively. The effect of added humic acid was significant in reducing the concentrations of total Zinc, Zinc bound to carbonate minerals, bound to oxides and residues. The maximum concentrations in case of not adding acid reached 9.313, 1.8957, 1.424, and 4.300 mg kg-1 soil, respectively, while the effect was positively in increasing available concentration associated with organic matter, as concentration in case of adding humic acid reached 0.851 and 1.4584 mg kg-1 soil, respectively. In the case of adding humic acid, this study is considered good for the results it showed in increasing the available zinc with the presence of humic acid, which is reflected in the plant growth and maintaining this element within the recommended concentrations. We determined Zn speciation in the soil system and evaluated the effects of humic acid application on the basic soil properties and Zn bioavailability.