Abstract: A pot experiment was conducted to detect the interaction effect of water and fertilizer on growth and photosynthetic pigments of Puelia sinense. The experiment was a completely randomized design with 9 factorial combinations of 3 levels of water [drought, 25% field capacity (FC); control, 75% FC; flooding, 100% FC)] and fertilizer (low, moderate, high levels of fertilizer). Above-ground biomass, below-ground biomass, total biomass, and root: shoot ratio were significantly affected by the interaction of water and fertilizer. For the control water treatment, a high level of fertilization led to increased tiller number and plant height, and greater below-ground, above-ground, and total plant biomass. This combination was the best among the 9 combinations. These results indicate that normal supply of water and high nutrient supply are the optimal conditions to achieve a high yield for this species. Both flooding and drought were detrimental to tillering and growth. However, under water deficit where a tillering reduction was observed, tillering capacity could be improved through fertilization. Under flooding, high fertilization was not beneficial and a moderate amount of fertilizer was sufficient for optimal accumulation of below-ground biomass. Plants in these conditions had a higher root to shoot ratio, possibly a plant response to hypoxic conditions. Compared to flooding, drought was more detrimental to the accumulation of above-ground biomass. In order to adapt to drought, P. sinense allocated more assimilate to the belowground organs. The increased root: shoot ratio was presumably advantageous for plant water capture and so to adaptation to drought. Interestingly, under water deficit stress, concentrations of photosynthetic pigments were significantly higher than those under control conditions. With increase in fertilization, contents of photosynthetic pigments also increased, especially when exposed to drought at the same time. These results elucidated some morphological and physiological adaptive mechanisms of this species when responding to water-deficit. Increased fertilization could mitigate the detrimental effects of water deficit stress on plant growth to some degree.