Abstract: In this article,the investigation was made that environment,production management and veterinary control records of 26,805 pigs from 9 large-scale pig in Yan′an comprehensively during 2005 to 2008.The survey showed that there was different degree of infection with coccidia in the all the pig farms,and the incidence rate is 1.8%-9.6%.By analyzing these cases,theses means,further strengthen environmental management and pay attention to pig health ventilation,should be kept to control coccidiosis by maintaining drug-control and helminthicide,based on different existed problems.