Abstract: In order to find the pathogens of the ulceration disease of Lateolabrax japonicus in seawater pond culture and the prevention and control methods of its diseases and pests, the diseased ulceration diseasal Lateolabrax japonicus were selected from Putian bacterials were isolated from the disease Lateolabrax japonicus and were confirmed to be the pathogen of the disease by artificial infection test. According to the results, morphological feature, physiological and biochemical characteristics were very similar to Vibrio harveyi. Experiments showed that Aeromonas hydrophila was sensitive to Cotrimoxazole, Amoxicillin, Piperacillin, Ticarcillin, Cefradine, Cefotaxime, Cefepime, Ceftazidime, Cefuroxime sodium, Meropenem, Cefoxitin, Amikacin, Netilmicin, Amikacin and other 14 kinds of antibiotics, but it was insensitive to minocycline, streptomycin and so on. By adding compound Cotrimoxazole and vitamin C in feed to the treatment of Lateolabrax japonicus skin ulcer disease in the actual production, continuous administration for 10 days, has obtained the good curative effect.