Winter buds of Potamogeton crispus were planted in the waters at different turbidities of 30NTU, 60NTU and 90NTU which were made by sand particles less than 100μm in diameter, and the effect of water turbidity on the germinating ratio and growth were examined. Some photosynthetic fluorescence characteristics were in situ determined by a developed, submersible, pulse-amplitude modulated (PAM) fluorometer, Diving-PAM. The germinating ratio of winter buds were shown to decrease significantly as the turbidity increasing on the 10th day of the seedling exposed in turbid water (p<0.05). However, the germinating ratio was as high as 100.0% in all turbidities on the 23th day. The seedling height and leaf number also decreased significantly while the water turbidity increased (p<0.05). The non-photochemical quenching (qN) significantly increased during the first ten-day the seedling exposed in the turbid waters, which indicated that the seedling leaves could increase heat dissipation to protect the photosystem Ⅱ (PSⅡ). During the first ten-day when the seedling exposed in the turbid water, quantum yield (Yield), photochemical quenching (qP) and Electron-transport rate (ETR) of seedling, were not shown to be influenced by the water turbidities. It demonstrated that photosynthesis of these seedlings was not limited by lack of light because the buds contain enough nutrients to support germination. The qP and ETR of seedling leaves were not significantly different among the turbid waters of 30, 60NTU and the control until the 23th day of turbid exposure, indicating no significant effect of the low water turbidity (30, 60 NTU) on seedling photochemical quenching and electron-transport rate. Significant decrease in the Yield of photosynthesis while the turbidity increasing (p<0.05) indicated remarkable effect of turbidity on photo supplying efficiency of PSⅡ reaction center. Moreover, the volumes of qP, ETR and Yield of seedling leaves were much lower in the turbid water of 90 NTU than that in the control water. ETRmax of seedlings decreased significantly (p<0.05) as the water turbidity increasing, demonstrating that the capacity of seedling leaves electron-transport decreased as the water turbidity increasing. The water turbidity showed great influence on photosynthetic capacity and growth rate of seedlings although no significant influence on germination of winter buds in turbid shallow water was observed.