This study investigated the neural effect of conflict context modulation of cognitive and affective conflict processing by recording evoked‐response potentials in cognitive and affective versions of a flanker task. By varying the proportion of congruent and incongruent trials in a block, we found different patterns of the context effect on evoked potentials during cognitive and affective conflict processing. For posterior N1 amplitude, frequent incongruent trials produced a larger effect only in the affective task. The opposite pattern of the context effect was observed for the central N450, which was enhanced by frequent cognitive but reduced by frequent affective contexts. We found similar context effect on the parietal sustained potential in both tasks. Overall, our findings suggest that cognitive and affective conflict processing engage a context‐dependent attentional control mechanism but a common conflict response system.