[Objective] To determine the cause of death for Taiwan Loach and screen sensitive drugs, a dominant bacteria strain Zy01 was isolated from of sick Taiwan Loach. This study will provide reference for further prevention and treatment of Aeromomas veronii in Taiwan Loach. [Methods] The pathogenic bacteria were isolated and purified from ulcerated muscle of Taiwan Loach. And the identification of phenotypic information of the strain Zy01 was conducted, including the biochemical identification and 16S rRNA gene sequence determination. The tests of artificial infection by using strain Zy01 to infect Taiwan Loach. Antimicrobial susceptibility test was conducted by K-B methods. [Results] Strain Zy01 was the pathogens of Taiwan Loach, the LC50 of the isolated was counted to 2.0×106 cfu/mL. According to morphological and biochemical characteristics as well as the result of 16S rRNA gene sequence analysis, the isolated strain Zy01 was A. veronii. Strain Zy01 was susceptible to ciprofloxacin, norfloxacin, azithromycin and gentamicin and other 10 kinds of antibiotics. Meanwhile, it showed resistance to oxacillin, penicillin, amoxicillin and other 9 kinds of antibiotics. [Conclusion] The isolated bacterial strain Zy01 was pathogenic to Taiwan Loach, and prevented by administering drugs such as gentamicin and neomycin in fisheries farming.