The present invention relates to an Internet keyword advertising method and, more par not ticularly, to an advertising method and system, which, when a user demands keyword searching, provides secondary keywords related to a corresponding keyword, thus allowing the user to find the actual information and / or commodity sought through keyword searching via the Internet, and providing corresponding data. Furthermore, the present invention relates to a method and system for providing a list of secondary keywords related to primary keyword search. In accordance with the present invention, a user conducts a search using a primary keyword having a relatively comprehensive meaning and then conducts searches more detailed secondary keywords, so that information and / or commodity sought by the user can be easily found and checked. Meanwhile, an advertiser discloses his or her information and / or commodity to effective customers, connected through corresponding secondary keywords, so that the efficiency of advertising can be greatly improved.