[Objective] The paper was to explore the cause of disease with symptoms of swelling joint, blanc-loose stool and few deaths, so as to provide suggestions and effective measures for diagnosis and control of the disease in chicken farm. [Method] The diseased chick samples were collected for bacteriological examination. Through bacterial isolation culture, PCR identification, biochemical test and animal test, 5 strains of S. pullorum were identified. [Result] When the isolates were inoculated into SPF chicks, the same disease cases with natural infection could be reproduced. [Conclusion] S. pullorum is the major cause of the disease in chicken farm.
