From the phenomena of “Three Teachings emerge from one source” in the history of Vietnamese thought, the article is the first step to explore within the scope of “Buddhist - Confucian aggregate” in the verses of Zen master Hương Hải. The Zen master contributed to the direction of thought of his time, specifically the “Buddhist - Confucian aggregate.” Zen master Hương Hải had few poetic works. However, his poemssufficienty help readers understand the idea of “Buddhist - Confucian aggregate” in the relationship of the Three Teachings from a multi-dimensional aspects of education, culture, religion, social politics, and self-cultivation. His poems also affirm the compatibility between the ideologies in the Three Teachings. The most prominent is the Buddha - Confucian relationship. The compatibility was an inevitable phenomenon in Vietnam in particular and East Asia in general.