This study was conducted to monitor the growth and development of Abies koreana seedlings in the Hallasan Mountain. Accordingly, the obtained results indicate that the number of A. koreana seedlings increased by 2.6 and 4.8 times in the Yeongsil and Jindallaebat areas, respectively, over the 10-year period. Most of these seedlings were found to be growing on moss-covered rocks. The average tree height over the last 10 years was obtained as 20.4 cm in the Yeongsil area and 3.6 cm in Jindallaebat with growths of 4.1 cm and 1.4 cm, respectively over the last 2 years. Of all the mature trees that were surviving in 2009, 6 died in Yeongsil in 2014 (with an additional 4 in 2018) and 13 in Jindallaebat in 2016. Over the 10-year period, the diameter at breast height of the trees in Yeongsil and Jindallaebat has increased by an average of 0.6 cm and 4.2 cm. Similarly, an average of 6.8 cones was found in the Yeongsil area in 2014 and 26.3 in Jindallaebat in 2016. However, in 2018, no additional cones were found in the former, although an average of 1.4 cones was observed in the latter. With respect to the average temperature and relative humidity, no significant difference could be observed between two monitored areas from 2016 to 2018. However, in July 2017 and February 2018, the average temperature was higher in the Jindallaebat area, while relative humidity was higher in Yeongsil, there by possibly affecting cone growth and flowering between areas. These results indicate the survival and growth of A. koreana seedlings in the Hallasan Mountain is sensitive to the environments of each area. Hence, continuous monitoring of the environment changes and in-depth studies on the flowering and fruiting of A. koreana seedlings needs to be carried out in order to analyze the relationship between their survival rates and changes in weather conditions.