The present invention aims at providing a sequential data examination method which can increase data examination accuracy compared with the prior art. The similarity is calculated between a layered network model generated from learning sequential data to be learned and a layered network model generated from testing sequential data to be tested. Based on the similarity, it is determined whether or not the testing sequential data to be tested belong to one or more categories. A network model for each layer of the layered network model is constructed by multiplying an element of the feature vector and its corresponding Eigen co-occurrence matrix.