175m-145m-175m project is carried out to regulate water level under normal circumstances, which results in periodic fluctuation of water level over 30m in the Three Gorges Reservoir. Different from most reservoirs, water level rose in winter while dropped in summer in the Three Gorges Reservoir. So, besides the case of being submerged for a long time, vegetations in the water-level-fluctuating zone suffered from two problems caused by those two factors described above. Both Acorus calamus L. and and Acorus tatarinowii S. are common kinds of wetland species in the Three Gorges Reservoir, thus the study on their growth and development in turbid waters would provide a scientific basis for selecting restoration species of the water-level-fluctuating zone in the Three Gorges Reservoir. Seedlings of Acorus calamus L. and Acorus tatarinowii S. were planted in water with turbidity of 30NTU, 60NTU or 90NTU respectively in August, in which the turbidity of the water was controlled by dispersing silt particles smaller than 100μm in diameter. The effect of water turbidity on the growth (such as sprouting number, leaf length, leaf width, leaf number) in two species of Acorus was studied in next spring. The rapid light responding curves of the leaves were determined in situ by a developed, submersible, pulse-amplitude modulated (PAM) fluorometer, diving-PAM. Sprouting rates in groups with different treatment groups were observed to be the same as those of the control group. In the water with turbidity of 30NTU, plants number of A. tatarinowii and A. calamus were significantly more than that of the control. Additionally, plants number of A. tatarinowii showed a distinctive trend to increase, but that of A. calamus exhibited the opposite trend. Moreover, leave length, leave width, total leaf number and total leaf length of two species plants in 30NTU treatment group were more than those of the control. In the water with turbidity of 60NTU and 90NTU, leave length, leave width and total leaf length of A. tatarinowii were remarkably lower than those of the control(P<0.05)). Furthermore, leaf length, leaf width and leaf number of A. calamus in 60NTU treatment group were significantly higher than those of the control group (P<0.01), whereas there was no significant difference (P>0.05) between 90 NTU treatment and the control. Meanwhile, the total leaf number and total leaf length of A. calamus in 60NTU and 90 NTU treatment groups were significantly lower than those of the control group (P<0.01). Measurement of the light responding curve in different treatment groups of two species of Acorus showed that photochemical fluorescence quenching (qP), non-photochemical quenching (qN) and relative electron transport rate (rETR) were remarkably decreased under the higher light intensity while qP, qN and rETR were significantly higher under low light intensity than those of the control. Moreover, the tolerance range of A. calamus under low light condition was larger than that of A. tatarinowii. In summary, A. calamus and A. gramineus could grow in shallow silt waters (water depth is 0.9 metre) for a long time, endued with the ability of drowning resistance in turbid water.