An experiment of the pearl culture was made in the low dike retaining waters and eco-logic eliminating snail (Oncomelania) of the lake beach of Dongtin Lake. The result shows that the waters are of favourable conditions for the pearl culture. During the dropping in water level and the drying of the lake beach in winter and spring, the low dike can maintain a depth of above 50cm of water. Mortalities of living snail (Oncomelania) and snail egg may reach up to 100%. Under natural conditions, the plankton in the water body of the pearl culture amounts to 30000 indivduals/L; dissolved oxygen 9.54-9.74mg/L, Ca²⁺. concentration 44.9±0.06 mg/L;pH value 6.9±0.13, H₂S and CH₄ 0 value in the water body of the pearl culture when water temperature is at 20℃. These states of the water chemistry and biology are suitable for the requirement of the mussel (Hyriopsis cumingii) growth. Production rate of the pearl of excellent quality may reach to 41.3%, being 13.5%, 15.9% and 23.4% higher than that of the inland lake (27.8%), mute river (25.4%) and pond (17.9%) respectively.