To the best of our knowledge, the application of LS-SVM modeling method to the packed towers has rarely been reported, especially for the purpose of soft sensor model development for the flooding velocity. Therefore, in this paper, the LS-SVM method is proposed to model and predict the flooding velocity to overcome the disadvantages of traditional models and the NN models aforementioned. With most kinds of packing data collected from the available literatures [14], a LS-SVM model is established for prediction of the flooding velocity. The results show that the proposed LS-SVM model has a good prediction performance for the flooding velocity