YANG Yuying。 ， YIE Jianqiang ，ZHAO Zhen—hua。 ， QIN Ai-jian ，GU Yufang

Abstract：A strain of Avian leukosis virus(ALV．J1 subgroup J was isolated from an adult broiler breeder folck．which had a history of myeloid leukosis(ML)．in Inner Mongolian．Moreover,another strain of ALV J was isolated from a ML case in Shandong．The two isolates were positive reaction in polymerase chain reactions with two pairs of primers specific for ALV-J and gave antigenically strong reaction in the indirect fluorescence antibody assay(IFA)with ALV-J specific monoclonal antibody JE9． The sequences of the 2．2kb PCR products of the tWO strains had 96．9％ homology,an d had 94．2％ — 95．4％ homology to strain SD9901 and YZ9901 AL＼LJ．