This study divided the life of Hujae Kim Gan into early age, middle age, and old age, and examined his poems under different themes, including “pursuit of Neo-Confucianism and introspection,” “trace of secluded life and joy of carefree life,” and “seclusion in forest and everyday feelings.” This study also explored how his inner consciousness is expressed in his poems in different periods. First, the poems under the theme of “pursuit of Neo-Confucianism and introspection” reflect his earnest feelings of fostering temper and pursuing Neo-Confucianism instead of external beauty of formality. The poetic expressions and their sources are mostly based on the scriptures. This shares the same context with the traditional poetic idea of Mencius and Xunzi, which seeks edification of custom, as well as preservation of conscience rather than finding the value and utility of pure literature in poems. Secondly, the poems under the theme of “trace of secluded life and joy of carefree life” are mainly about his craving for completely secluded life and unworldly point of view compared to his previous works that feel somehow heavier with Neo-Confucian ideas. Lastly, the poems under the theme of “seclusion in forest and everyday feelings” mainly cover the secluded and simple vibes he felt throughout his secluded life in forest. These poems show the feelings and daily life of complete seclusion in forest, which he desperately longed for since his youth years. To the scholars of the times and coming scholars, Kim Gan(金榦) is regarded as a scholar who deeply immersed into the Neo-Confucianism. In fact, he lived a secluded life from his early age to devote his whole life to the Neo-Confucianism. He also deemed the continuance of studies and training of upcoming generation as his lifetime task, and a lot of his poems include Neo-Confucian ideas and Neo-Confucian thoughts. However, his poetic world was not completed covered with Neo-Confucian ideas. Instead, there are poems about his pursuit of secluded life and his actual unworldly secluded life. These poems show his aspects as a poet Kim Gan(金榦) who escaped from the Neo-Confucian ideas as a scholar.