Abstract: A chicken farm of Guizhou Province were sent to check six paradigms of invasive chickens,according to Epidemiology dissection lesion they were suspected Marek’disease,then it was not bacterial growth from the liver to be isolated and cultured after 24 h,agar diffusion reaction were positive,the expected purpose fragment could be amplified from the extracted Marek’viral nucleic acid by the PCR assay developed.The results suggested that this loemiawas caused by Marek’s disease infection.The test is some great significance for exact diagnosis and effectual control the disease.