Previous studies have investigated the time course of emotion effects during emotion-word processing, but no consistent pattern has emerged. Notably, most of these studies intermixed emotion-label words (e.g., "happy") with emotion-laden words (e.g., "successful"), although emotion activation differences for these two types of words have been documented. Here, we separately investigated the time course of the emotion effects of emotion-label and emotion-laden words with a lexical decision task. The results showed that emotion-label words and negative emotion-laden words elicited a larger P2 than did neutral words, whereas there was no difference in P2 between positive emotion-laden and neutral words. Furthermore, both emotion-label and emotion-laden words, regardless of their valence, elicited smaller N400 components than did neutral words. These results suggest that the emotion effect of emotion-label words occurs earlier than that of emotion-laden words, but this difference is limited to the positive valence category.