A method and an apparatus for identifying synonym and utilizing such synonym to conduct search is disclosed. The disclosed method includes: obtaining arbitrary two words to be identified; determining whether a shortest edit distance between the two words less than or equal to an edit distance threshold; determining whether the two words to be identified exist in a preset knowledge database, and if an answer is yes then searching a smallest granularity type with highest weight value for each word in the knowledge database; and if the two word have the same smallest granularity type with highest weight value, then determining such two words are synonyms, or non-synonym otherwise. The disclosed techniques greatly improve accuracy of synonym identification and guarantee effect of synonym identification.