Metaphor has been used in designing computer systems for 20 years. With the mergence of more advanced technology as well as the emphasis of user-centered design in the recent decade, its application in information systems has increased tremendously. Literature from several areas regarding interface metaphor are reviewed in this paper, including an overview of interface metaphor, the way it relates to our daily life, the function of metaphors and mental models, and the design of metaphor in user interface. The final section is a review of metaphor studies focusing on the comparison of single and multiple metaphors in interface design.