Abstract: In the winter, the operating efficiency of ecological beds is not satisfied. Four psychrophilic bacteria were cultivated and separated, and their physiological characteristics were tested. The experimental result shows that the growth rate of the mixed psychrophilic bacteria can reach to 0. 058 h^-1, but that of the mesophilie bacteria is zero. The operating efficiency was greatly improved after adding some psychrophilic bacteria, and the removal ratio of Zn is 25 times than that adding no psyehrophilic bacteria.