Although the back-propagation algorithm can build accurate classification models, it can not discover the sub-categories in the data set. To solve this problem, this study proposed a novel neural network model, Sub-Category Neural Network (SCNN). To prove the performance of SCNN, two artificial classification problems as well as one actual forest cover classification problem were employed to test and compare with back-propagation network (BPN). The results proved that the accuracy of SCNN is about the same as BPN, while it can discover the sub-categories in the data set.