To investigate clonal growth and foraging behavior of a submerged macrophyte Vallisneria natans, biomass, ramet number, bud number, total stolon length, shoot height and maximum root length responses of V. natans ramets were investigated experimentally at five water depths (1.0, 2.5, 4.0, 5.5 and 7.0 m). The study showed biomass, ramet number, bud number, total stolon length and maximum root length all decreased significantly with increasing water depths. The shoot height exhibited a unimodal pattern along with increasing water depths, with the maximum value at the water depth of 2.5 m. The plant biomass significantly affected all the growth traits except for the bud number. Furthermore, ramet number and total stolon length were significantly affected by the interactive effect between water depth and plant biomass, suggesting that the effects of water depth on ramet number and total stolon length were depended on plant development.