In the vicinity of Baiyanhua Railway Station of Inner Mongolia Autonomous Region，there are over 20 pools and one large lake where a great many of conchostracans are living. The author has made investigation on the conchostracans habits including swimming，feeding，copulative way，etc. and their living environment including the pool size，water temperature，water pH and air temperature. The conchostracans commonly live in shallow waters,such as the shallow water areas along the  margins of the pools and lake，and they swim slowly(about 1 cm/s). During copulating，they stop in some place. The male moves water containing his spermatozoa by his appendages and lets the water flow into the females two valves(namely between its body and two valves). As a result, the female ova are fertilized. These facts indicate that they adapt only to quiet water or an environment in which water flows sluggishly. Comparison of both the modern environment and the palaeoenvironment of conchostracans shows that the two environments are very similar to each other. Therefore，the investigation of living conchostracans ecology and environment is of important significance for palaeoecological and palaeoenvironmental reconstruction.