The purpose of this study was to analyze the patent and design patent cases invented by Korean architectural and engineering (A&E) firms searching for current trend of applicants and building technology. Korean A&E offices registered about 2,700 patents between 2003 and 2013, placing 65% ratio in the Section E, Fixed Constructions. Registration numbers of building patents have been increased rapidly between 2005 and 2007 affected by Pre Qualification and construction industry. Patent registration has been ranked from the first Finishing works E04F, Foundations E02D, General building constructions E04B, Doors & windows E06B, Installation of electronic cables H02G and to last Forms E04G. Korean A&E offices have researched and developed patents focusing on Stairs, Forms for general and special, Arrangements for doors & windows, and Fences. To the contrary of technical patents, design patent and building layout for particular purposes E04H have little grown because of regulation and information.