Abstract <p>Soil surface charges play an important role because they help in understanding and improving soil characteristics and its physical and chemical properties, such as its ability to store nutrients necessary for the plant, control the movement of different ions and regulate the degree of soil reactivity. They also strongly influence the response of plants to changes in the soil solution as a result of adding fertilizers, for example. The factors that determine or influence the point-of-zero charge (PZC) of soils were examined on different Luvisols sampled in Syria. The pH-dependent variable charges were measured using potentiometric titration curves. These curves showed variability in the PZC locations of the study samples, as well as in the amounts of variable charges, which differed both between the studied profiles and within the same profile. The PZC values for the studied samples ranged between pH values of (3.92 and 4.96), and all PZC values were found to be below the soil pH, indicating that the studied soils possess negative charges at their natural soil pH values. An increase was observed in the amounts of positive charges compared to the negative charges for all the horizon samples studied. The positive charge amounts for the first profile samples ranged between 12.8–15.8&#xa0;cmol(+)kg^–1, while the negative charge amounts ranged between 8.6–9.6 cmol(+)kg^–1. For the second profile samples, the positive charge amounts ranged between 23.8–30.7 cmol(+)kg^–1, and the negative charge amounts ranged between 9.2–10.2 cmol(+)kg^–1. The difference in rainfall can effectively explain the difference in some properties of the two study soils despite the similarity of the parent materials, thus determining the PZC and buffering capacity of the two soils.</p>