In order to reconstruct the landscape of an ancient capital city and its living landscape as close as possible to how it may have actually been, it is necessary to identify its green space (by identifying how the vegetation within the landscape looked like, where it was located, and what it meant to the ancient people who lived there), in addition to understanding aspects of its civil engineering and architecture. This research reveals the vegetation change that took place at five archaeological sites in Gyeongju during the time from the Three Kingdoms to the Unified Silla Period, with a focus on the places where vegetation grew, by examining the findings of various plant remains, with focus on pollen analyses. According to the analysis, the cultural meaning of the vegetation which formed part of the landscape of the ancient capital city of Silla is as follows. During the period from the fifth to the sixth century AD, a riparian forest dominated by Zelkova-Ulmus was distributed along the banks of the Nam-cheon and Buk-cheon Rivers; the findings of the research suggest the possibility that the expansion and decline of this forest may have resulted from certain human activities. Evidence from this research suggests that the extinction of the wetland vegetation in the central area of the Gyeongju Basin in the late sixth century may have been due to the development of lowland areas for land required by the capital city. From the Unified Silla Period, the areas peripheral to settlements within the Gyeongju Basin appear to have witnessed a relative decrease in forest lands, as a result of the expansion of city development and an increase in its population; this is evidenced by the increase in the proportion of grassland. Meanwhile, in mountainous areas, the Quercus-Pinus climax forest declined while secondary pine forests increased. In addition, this research discovered the presence of ancient exotic plants that had been imported through the trade with foreign countries, especially newly cultivated plants which began to appear and become diversified during the Unified Silla Period. The empirical data of this research, which was produced by collecting and classifying landscaping plants of the time, can provide a better resource based on which the variety of the plant culture of the capital city of Silla may be assumed.