Abstract: The enzyme-linked immunosorbent assay (ELISA) method was used in the present study to detect five endogenous hormones in various tissues (or positions) of four sympodial bamboo species, including Yanghuang Bamboo (scientific name not to be determined), Dendrocalamus farinosus, Bambusa rigida, and Neosinocalamus affinis, during the shooting and young bamboo stage. The results showed that: 1) Overall, the order of hormone content was abscisic acid (ABA)> indoleacetic acid (IAA)>cytokinin (CTK)>gibberellic acid (GA)>brassinolide (BR), but the bioactivity may be just the opposite; 2) Based on the distribution of tissues (positions), the contents of IAA, or CTK, or BR in bamboo shoots or young bamboos were statistically the same in the upper, middle and bottom positions (except Yanghuang bamboo, the CTK content in the leaves of 1-yr-old bamboo was significantly lower than that in other tissues). For ABA content, the trend was middle ≥ bottom > upper, but for GA content, the trend was middle > upper > bottom. 3) The five hormones displayed strong synergistic effect and they were related to the activities of growth and differentiation of specific tissues or positions. Generally, IAA, ABA and GA showed a "high-low-high" variation,, while CTK and BR showed a "first high and then low" or "first rise and then fall" variation during the shoot-young bamboo stage. 4) The dynamics of these endogenous hormones in sympodial bamboos with the development stages might be determined by the urgent demand of cell division, internode elongation and branch (leaf) emergence. Among them, ABA might be related to the degree of water demand and the soil moisture, while GA was more specific than other hormones in controlling the height growth of bamboo shoots and young bamboos. The present study can provided fundamental data for hormone regulation of growth and yield of sympodial bamboo forests.