Abstract: This experiment was to explore platelet parameters change in Guangxi Bama miniature pig infected by porcine circovirus-like agent P1.Twelve Guangxi Bama miniature pigs at 1 month of age were randomly designated to two groups of 6 each. Group 1 pigs were each injected into the superficial inguinal lymph nodes with the cloned P1 plasmid DNA and pigs in group 2 served as controls. The peripheral blood platelet parameters of the pigs were detected with the automatic hematology analytic instrument at 3,8,17,24,31 and 40 days postinoculation （dpi）.The statistic results showed that the mean platelet volume（MPV） were no significant difference between two groups. However, the platelet total（PLT） and plateletcrit（PCT） in porcine circovirus-like agent P1 infection were significantly decreased at 8 dpi （P〈0.05） and platelet distribution width （PDW） be at 17 dpi （V〈0.05）.