To explore the occurrence condition, direction and intensity of water physiological integration in bamboo, an experiment with connected Indocalamus decorus clonal ramets under three water potential gradients of soil matrix (90%-60%, 60%-30%, 90%-30%) and three matrix relative water content (90%±5%, high water potential; 60%±5%, intermediate water potential; 30%±5%, low water potential) was conducted, and the activities of antioxidant enzymes and the contents of soluble protein and MDA were determined. The results showed that the contents of MDA and soluble protein and the activities of CAT and POD increased, while SOD activity decreased with the increase of treatment time. With the increase of water potential difference between I. decorus ramets, CAT and SOD activities and soluble protein content of ramets under the low water potential increased, while POD activity and MDA content decreased; but ramets under the high water potential had an opposite pattern. Antioxidant physiological indicators of ramets under the intermediate water potential had no significant differences during the treatment time. Our study indicated that water physiological integration existed in I. decorus clonal system under heterogeneous water environment and ramets needed first to guarantee its own water demand. Intense water transfer from high water potential ramets to low water potential ramets would take place when water surplus and deficit existed between ramets. The bigger the water potential difference of ramets, the stronger the intensity of physiological integration. Clonal ramets had “selfish” and “altruistic” behaviors on water physiological integration. This study provided a theoretical basis for artificial water supply of commercial bamboo forests.