Clean water is unique and invaluable natural resource without which our life would be impossible. Nowadays, humanity is facing a global decline in freshwater, the primary source of drinking water, due to increase in water demand, consumption and high water pollution. Therefore, the primary task of almost all national and international humanitarian organizations has become to provide sufficient amounts of drinking water. The presence of natural organic substances in water is an undesirable phenomenon because it negatively affects the color, smell and taste of water. In addition, elevated concentrations of natural organic matter in water can contribute to the growth of microorganisms in water supply systems and make it difficult to remove iron and manganese from water. Natural organic substances also act as precursors in the formation of halogenated organic compounds during water disinfection, therefore one of the basic tasks of the water treatment process is removal of natural organic matter from water. Numerous qualitative analytes have determined the dominant proportion of humic acid in the mixture of natural organic substances present in the waters. One of the effective methods of removing natural organic substances from water is adsorption on activated carbon. The aim of this study was to examine and compare the efficiency of humic acid removal from model solutions by adsorption on two species commercially available activated carbon, Cullar D (Culligan Italy) and Hydraffyn 30 N (Donau Corporation, USA). The efficiency of these activated carbons in removing humic acid was determined by monitoring the humic acid concentration after water treatment by adsorbent depending on the initial humic acid concentration, adsorption time, adsorbent mass and water pH.