Disclosed are a method and system for proposing an advertisement keyword. The method includes receiving an input of a keyword associated with a new advertiser, extracting a representative keyword from among advertisement keywords of an existing advertiser having an outcome of a prescribed reference value or more, comparing a keyword inputted in association with the new advertiser and the representative keyword of the existing advertiser, determining whether the new advertiser has the same business category as that of the existing advertiser based on the compared result, designating a predetermined keyword-set as a business category keyword based on the determined result, and proposing the advertisement keyword to the new advertiser based on a result obtained by analyzing the business category keyword.