Abstract: With continuous culture in laboratory, this paper studied the individual’s growth and population dynamics of Paramecium caudatum under the stress of methamidophos, fen-propathrin and 2,4-D buiylate, with the population growth curves analyzed by using Logistic model. The results indicated that methamidophos and fen-propathrin could alter the cell size and form of P. caudatum.After treated with different concentrations of test pesticides, the population growth curves were all sigmoid, and accorded well with Logistic model (R²＞0.8). The K value was decreased significantly under the stress of pesticides, and the maximal population growth rate was lower under methamidophos and fen-propathrin stress than under 2,4-D buiylate stress and the control.

Key words: North side of Qingliang Mountain, Macrofungi, Ecological distribution