PEDV infection affected the activation of mitogen-activated protein kinase (MAPK) p38, extracellular regulated protein kinases1/2 (ERK1/2), and c-Jun N-terminal kinases (JNK). Vero cells were infected with PEDV (0.1 MOI) at 4, 8, 12, 24, and 36 h post-infection (h.p.i.). The cells were collected after different lengths of time for Western blotting. An equal amount of protein was subjected to Western blotting analysis. (A) Levels of phosphorylated and total MAPK p38, ERK1/2, or JNK were analyzed by Western blotting. Beta-actin was used as a loading control. (B) Levels of phospho-p38/total p38 were plotted using ImageJ. (C) Levels of phospho-JNK/total JNK were plotted using ImageJ. (D) Fold changes in the phospho-Erk/total Erk ratio were plotted using ImageJ. p-values less than 0.05 were considered statistically significant (** p < 0.01). Bars represent standard deviations.