Abstract: Taking sulfamethazine ( SM1) ,enrofloxacin ( ENR) ,chlortetracycline ( CTC)and trime-thoprim ( TMP) as the research objects,the degradation processes of typical antibiotics in aquaculturewater,as well as their distribution and degradation in water-sediment system were studied by controlexperiments. The results showed that in aquaculture water,the hydrolysis half-lives of SM1,ENR andCTC with the initial concentration of 50 μg·L-1 were 152.6,115.9,and 59.2 d,respectively,whileTMP hardly hydrolyzed. Under simulated sunlight with light intensity of 3 000 lux,the photolysis half -lives of SM1,ENR,and CTC were 17.4,33.0,and 3.5 d respectively,while TMP hardly photodegraded.The biodegradation half-lives of SM1,ENR,CTC and TMP were 31.3,328.5,5.3,and 259.6 d,respec-tively. The comprehensive degradation rate of each antibiotic was faster than the degradation rate of anysingle reaction. In the water-sediment systems of 3 different aquaculture types ( fish,shrimp,crab) ,allthe four antibiotics in the aqueous phase decayed rapidly within 0~7 days. At equilibrium,the adsorp-tion coefficients ( Kd) of SM1,ENR,CTC and TMP were 1.52~3.12,26.65 ~40.44,4.79 ~12.05,and1.16~3.85 L·kg-1,and there were obvious differences in the adsorption coefficients of antibiotics indifferent system. In sediments,the degradation half-lives of CTC and TMP were long ( 29.1 ~60.5 dand 26.7~42.5 d) ,while the half-life of SM1 was short ( 8.2 ~20.5 d) . The half-life of ENR variedgreatly in different sediments. The persistence of antibiotics in sediments was generally higher than thatin water. Close-