Isfahan’s Qajar houses can be discussed studied from diffrent angels including the decoration used in them. These luxurious, spacious houses all belong to reputed families. Some houses were built in Safavi era and then, they have been rebuilt by the owners.The others, however, were erected in Qajar period and outnumber their Safavi counterparts. Today, the houses are destroyed, deserted or resided by their owners.Unlike the claims which were made regarding the architectural decorations in the Qajar era, they show the pinnacle of art in the decorations of the time. Colored sash windows, latticed-work windows, plaster-molding and mirror-work, elegant wall paintings, tile-work, carving, and finally the type of wonderful house architecture arouse admiration of every spectator using the field method, the study tries to introduce the overall Qajar houses of Isfahan and classify the different types of decorations used in them. It also concentrates on plaster-molding of these buildings in a comparative-analytic manner. To this end, a number of these houses with the most architectural decorations and various kinds of plaster-molding have been studied and compared.