This paper introduces the application of logistic curve in agricultural science, and gives a division method of parameter estimation of logistic curve. Because the logistic curve contains three parameters, it is not possible to use least square method to estimate the parameters directly. In this paper, the parameter C is estimated by the three (four) point method at first. Then the two steps method is used to estimate the parameters b and a respectively. Through a practical example with the new method, the example shows that the precision of this method is relatively high.