What does chronological study of historical wooden architecture mean? And, what is the Annual-ring Chronology and why do we need it for the study of wooden architecture? What is the relationship between these two? What is the reason for me limiting the subject of this study to the late Joseon period? A wooden building needs to be repaired on a regular basis to use for a long period, and therefore, it is often difficult to maintain its original style. As the main material of a wooden building, wood tends to be damaged by insects or natural decay and erosion, and the work of repair or replacement is often unavoidable. A wooden building is a complete work of art when it is first completed in terms of practical function and artistic style and structure, but this completeness becomes damaged over time, gradually losing its original shape and structure. At the same time, we sometimes need to eliminate a considerable part of the original materials, replacing them with new ones. Replacing the original with new wood does not necessarily mean any significant change in the structure of the building, and thus, not a great loss of the original's artistic value. However, if architects use a different material from the original in repair work, or if they follow the trend of their time rather than that of the original, the building may end up having varied styles within. This can cause a problem for researchers to ascertain an exact construction date of the building. For most wooden buildings, repair is absolutely unavoidable to extend its life, and therefore, it can have various styles from different periods. This is why we sometimes find it difficult to discuss wooden buildings in terms of styles according to periods. Therefore, to produce a precise chronology of a wooden building, a researcher should carefully review not only the original construction date, but also the history of repair works via, for example, primary data such as a written record on a rainbow beam. Despite that, it is still necessary to check the repaired part in a direct manner depending on the researcher's naked eye, and divide the new from the old. One problem in this process is related to the study of bracket set under the eaves, which are often decorated with traditional color patterns. For an old building with a long history of repair, it is not easy to identify a temporal order of repaired parts, partly due to the color decoration. In a situation where old and new materials coexist, a study of architectural style can face a major obstacle, particularly concerning the changes of style and the reason. One of the scientific means that is useful in dealing with such a situation is the tree-ring dating. It was in November of 1999 when Korea introduced this methodology in which let researchers overlap annual rings of wooden materials used for an architectural building with those of living trees, but did this in real time. After the first try of Professor Won Kyu Park, a leading dendrochronology expert, and I conducted a joint study on the topic for three years between September of 2000 and August of 2003. Thanks to the results from the study, we are now able to present a precise chronology on the cutting dates of original wood elements used for historical wooden buildings of the late Joseon era, meaning that we now know the exact age of buildings studied. In the course of analyzing the samples collected from the repair works of wooden building in which I took part, and based on the Chronology of Old Wooden Materials of Geunjeongjeon Hall and Geunjeongmun Gate in Gyeongbokgung Palace, we completed 'a Master Chronology for 580 years starting from 1420. This means that we are now able to give specific dates for wooden buildings built since, at least, since the 16th century. We will also be able to give dates for buildings before the 15th century once a following annual-ring study on the buildings before 1420 is completed. In this paper, however, I have focused on the buildings of the 17th century and post 17th century, and attempted to review the chronological methodology in the field of architectural history by comparing the absolute dates of old wooden materials with the existing chronology.