Swamp soils are characterized by physical and chemical properties influenced by hydrological conditions and the distance from rivers. This study aimed to analyze differences in clay content, soil pH, total potential acidity (TPA), and exchangeable aluminum (Al-dd) in swamp land based on the distance from the Negara River in Tapin Regency, South Kalimantan. A field survey method was employed using purposive sampling to collect soil samples from two locations, approximately 0.2 km and 20 km from the Negara River. Soil samples were collected from 20 observation points and analyzed in the laboratory to determine clay content, soil pH, TPA, and Al-dd. Data were analyzed using F-test and t-test. The results showed significant differences in all observed parameters between the two locations. Soil at a distance of approximately 0.2 km from the Negara River exhibited a clay content of 84.48%, soil pH of 4.49, TPA of 12.53 cmol(+)H⁺ kg?¹ soil, and Al-dd of 3.18 cmol(+) kg?¹. Meanwhile, soil at a distance of approximately 20 km from the Negara River showed a clay content of 64.72%, soil pH of 5.30, TPA of 3.88 cmol(+)H⁺ kg?¹ soil, and Al-dd of 1.29 cmol(+) kg?¹. The higher clay content, TPA, and Al-dd values at the location near the river were associated with tidal influence and more intensive sedimentation. It conclusion, that the distance of the land from the Negara River influences the physical and chemical properties of swamp soil, specifically clay content, soil pH, total potential acidity, and exchangeable aluminum.