ObjectiveTo investigate the changes in perforin (PRF) and granzyme B (GrzB) of CD8+ T cells and NK cells in children with handfootandmouth disease (HFMD) caused by enterovirus 71 (EV71).Methods30 children with common HFMD(common group), 30 with severe HFMD (severe group), and 30 healthy children volunteers (control group) in a hospital in MayJuly 2017 were selected, expression levels of PRF and GrzB in CD8+ T cells and NK cells in peripheral blood were detected by flow cytometry, differences among three groups were compared.ResultsCompared with control group, expression levels of PRF and GrzB in two kinds of cells of children with common and severe EV71 HFMD at acute stage were significantly higher, difference were both significant (both P<0.05). Expression levels of PRF and GrzB in CD8+ T cells of children with common and severe EV71 HFMD at convalescent stage were significantly lower than those at acute stage, but still higher than those in control group (both P<0.05). Expression levels of PRF and GrzB in NK cells: there was no significant difference between common group and severe group at acute stage (both P>0.05); compared with acute stage, at convalescent stage of common EV71 HFMD slightly increased, but difference was not statistically significant（both P>0.05）； at convalescent stage of severe EV71 HFMD were significantly higher than that in the acute stage (both P<0.05).ConclusionPerforin and granzyme B in CD8+ T cells and NK cells play a role in the pathogenesis of EV71 HFMD.