Abstract: We have shown that some growth substances existed in water chestnut. These substances could be extracted with alcohol, adsorbed on active carbon and retained on the anion exchange resins which could be eluted with 3N formic acid. The physiological activities were shown to be capable of promoting the callus growth of Par thenocissus tricuspidata Pench and Nicotiana tabacum L.; accelerating the callus formation of Vitis vinifera L.; inducing the bud formation from cambium of N. tabacum L.; the root formation from the cutting of Hibiscus syriacus L.; the breaking of dormancy of potato tubers; the growth of pea and rice embryos cultured in vitro and stimulating the growth and spore formation of Aspergillus niger van Tieghem. However, these growth substances were not effective toward the straight growth of wheat coleoptile, neither effective towards the growth of rice seedlings nor the retention of chlorophyll in detached leaves. Bioassay and preliminary chemical identification shown that the effective substances for growth in water chestnut probably are not due to auxin, gibberellin or cytokinin.