Abstract: The statistical relationship between feature vector and quality index is built by regress analysis and then the quality index is expressed to the regress function of feature vector. By this means, a statistical mapping relation between in.feature space and quality index space is built and a online pattern recognition method based on the statistical mapping space is provided through the clustering in quality space and classification in feature space. The validity of the method is verified by the simulation results of the data from Sinter factory of Tangshan Steel Corporation. From the algorithm analysis and simulation results, this method can effectively overcome the pattern intercross and can be used for complex production process quality online prediction.