Growth responses of Hydrilla verticillata to increasing water levels were examined in this experiment. The plants were cultured in pots, which were submersed in water and dropped downward the lake bottom at different speeds. The results show that different rising rates of water level had significant influence on the stem lengths, which were 50 cm/5 d > 30 cm/5 d > 10 cm/5 d > 70 cm/5 d. However, no obvious differences in the stem length were found between the groups of 10, 30 cm/5 d and control groups. At the group of 50 cm/5 d, the growth rate in stem length rose at 3.7 cm/d; however, the group of 70 cm/5 d died at the 49th day. Besides, the rising of water level also significantly affects the number of branches of H. verticillata. Comparing to the control groups, went up, the node number of H. verticillata declined with the rising water level rates. Obvious differences were found in the number of nodes, leaves and length between different water level rising rates groups. With the water level rising rate increased, the number of nodes followed the trend of increasing first and then declined; numbers of leaves became fewer and the node spacing extended. Compared with the control group, the numbers of nodes and leaves are less, and the node spacing enlarged. With increasing of the rising rates of water level, its biomass declined and the differences were extremely significant. These indicated that, to get as much sunlight as possible, H. verticillata changes the plant morphology and reduces the biomass to adapt to the rising water. However, owing to the inability to accommodate itself to the stresses caused by the lack of sunlight, it would die under the water rising to 70 cm/5 d.