Abstract: The sorption behavior of sediments is a key process that regulates the transport and transformation of antibiotics in the ecological environment. Differences in the physicochemical properties of sediments in different regions will affect the adsorption behavior of antibiotics directly. An in-depth investigation of the action mechanism and the establishment of a corresponding adsorption prediction model are essential to improve the accuracy of environmental risk assessment. In order to predict the adsorption of antibiotics in the water-sediment system more accurately, estuarine-offshore sediments from different regions of the Yangtze River Delta were collected, the adsorption characteristics of tetracycline (TC) and ciprofloxacin (CIP) in the sediment were analyzed and a region-specific prediction model was constructed. The results showed that the kinetic adsorption process of TC and CIP on sediments conformed to the pseudo-second-order kinetic model, and the isothermal adsorption process conformed to the Freundlich isothermal adsorption model and linear model. Combined with the correlation analysis of physicochemical parameters and adsorption properties of sediments from different regions, a prediction model for the adsorption partition coefficient (K_d) of estuarine and marine sediments was established using partial least squares (PLS) regression, which had excellent prediction accuracy (cross-validation coefficient Q²＞0.85). The adsorption capacity of TC and CIP was significantly higher in sediments from the North Passage of the South Channel and the muddy area of the Yangtze River Estuary than those from the South Passage of the South Channel and the distant sea area of the Yangtze River Estuary. Additionally, the adsorption capacity of TC was higher than that of CIP in sediments from the same location. The predictive model effectively estimates the adsorption performance of the two antibiotics in different sediments of the Yangtze River Delta, providing a theoretical basis for assessing their contamination risk in estuarine and marine areas. The BRIEF REPORT is available for this paper at http://www.ykcs.ac.cn/en/article/doi/10.15898/j.ykcs.202506190169.