Abstract: Raising chickens in orchard has been widely developed in China, serving as a popular ecological breeding mode, due to the direct usage of chicken manure as a fertilizer to achieve comprehensive utilization of land resources and agricultural wastes, and thereby to reduce the addition of herbicides and insecticides. However, the organic matter and antibiotics leaching from the chicken manure have posed a potential pollution risk on the orchard soil and the surrounding water environment. Research on the co-transport behavior of manure-derived dissolved organic matter and antibiotics is lacking, particularly on the relevant mechanism. This study aims to investigate the migration characteristics of dissolved organic matter (DOM) in chicken manure, and theirs effects on the adsorption and leaching features of sulfadiazine (SD), florfenicol (FFC) and tylosin (TYL) in an orchard in the typical calcareous purple soil area of central Sichuan, China. Batch equilibrium and packed soil column experiments were carried out using the combined techniques of spectroscopic characterization. The results indicated that tryptophan was the main component of the tested chicken manure DOM, to increase the adsorption sites for antibiotics on the soil surface, indicating a stronger adsorption in soil, compared with that of humic acid. The isotherm adsorption of three antibiotics fitted well by both the linear and Freundlich equations, indicating a physical adsorption process dominated. There were weak adsorption capacities of SD and FFC in the studied orchard soil. Their adsorption almost remain constant, when spiked simultaneously with chicken manure DOM (200 mg/L). In the case, the adsorption of SD and FFC increased significantly (P<0.05), when the chicken manure DOM was introduced to the soil in advance. The corresponding Kf values for SD and FFC increased by 77.28% and 114.36%, respectively, due to the binding of antibiotics to the previously adsorbed chicken manure DOM on the soil surface via a mechanism of noncovalent interactions. There was a strong absorption capacity of TYL in the tested soil. TYL was not sensitive to the presence of chicken manure DOM in its migration process for most soil adsorption sites. Under a simulated rainfall of 20 mm/h, SD and FFC were highly mobile, leaching out almost simultaneously with the water flow tracer Br- from the soil column. Being consistent with the results from the batch experiment, the chicken manure DOM in the treatment of injection prior to antibiotics delayed the breakthrough of SD and FFC by 0.49 and 0.25 PV, and their total leaching amount decreased by 12.04% and 15.35%, respectively. The decrease leaching of SD and FFC also occurred in the treatment of simultaneous injection of chicken manure DOM and antibiotics. Most residues of TYL retained in the topsoil without penetrating, indicating that the chicken manure DOM had no impact on the leaching of TYL. Therefore, for the highly mobile antibiotics, the chicken manure DOM can be expected to increase the retention of antibiotics in the soil through a co-adsorption mechanism. The finding demonstrated that the adsorption of tryptophan from chicken manure DOM can pose a significant blocking effect on the leaching of weakly adsorbed antibiotics in the co-transport process of manure DOM and antibiotics in soil due to chicken raising