Metaphor is a cognitive process that enables people to make mental mapping across distinct conceptual domains. The present study investigated metaphorical and literal meaning access in metaphor comprehension, and the effects of working memory load and mental imagery on metaphor comprehension. Three sentence priming experiments were conducted and the results showed that the literal meaning of a metaphor was accessed faster than the metaphorical meaning, but metaphorical meaning could be accessed as quickly as literal meaning if there was more cognitive resource involved. These findings indicated that the literal meaning of a metaphor is accessed first in the early stage of metaphor comprehension, and working memory load plays an important role in the process. The study didn't find any significant effect of ima-geability on metaphor comprehension; however, the results implied the metaphors with low imageability need more working memory load to understand. The implication for natural language processing of the computer science was discussed.