Disclosed herein are a method, an apparatus, and a computer readable recording medium for a search using extension keyword. According to an aspect of the present invention, there is provided a method for a search using extension keyword, the method including mapping search keywords transmitted from a user terminal to at least one concept keyword, extending the concept keyword to plurality of concept keywords having association with each other so that a concept keyword extension data-set is generated, and generating extension keywords corresponding to the concept keyword extension data-set.