The purpose of this study was to evaluate the effect of a subsequent infection of PCV2 on piglets with PEDV. The results obtained were as follows: Antibodies against PCV2 and PEDV were detected at 24, 36, 48, 60 and 72h postinfection. And the antibody titers of alone infections with PEDV were gradually reduced and increased from 60 hpi to 72 hpi. Whereas, the antibody titers of dual infections with PCV2 and PEDV were gradually reduced all the time. PEDV antigens were detected at 24, 36, 48, 60 and 72 hpi, being seen almost exclusively in feces and small intestines from PEDV-infected piglets and PCV2-coinfected piglets. The detection rate of PEDV in feces and jejunum tissues by RT-PCR were 94.9% and 91.1% in dual infections and 87.1% and 83.6% in alone infections with PEDV, respectively. In dual infected piglets, significantly more PEDV antigens were detected in the feces and small intestines tissues at 24 hpi (P<0.05) than in the same feces and tissues of the alone infected piglets. Thereafter, at 72 hpi significantly more PEDV antigens (P<0.05) was detected in the jejunal tissues of the dual infected piglets with than of alone PEDV-infected piglets. The detection rate of PEDV antigen in the duodenum, jejunum and ileum by IFA were 91.3%, 91.3% and 83.3% in dual infected piglets and 75.0%, 83% and 75% in alone infected piglets, respectively. Intense and specific fluorescence signals were more often seen within jejunal villous enterocytes in dual infected piglets than alone infected piglets.