Abstract: A simulating model of artificial neural network, which has the ability to describe the nonlinear relations between plant root and shoot, was established. The purpose was to calculate the growing factors of roots by using the parameters of shoot in the model. The identified BP method was also used for getting the optimization. Accurate test of potted cultivatation was conducted for offering enough training samples and testing samples to validate the model. The result indicated that the model of artificial neural network is of high precise to simulate relations of root/shoot, and is valuable for practical uses.