Abstract: Based on Grey system, an serial weakening step by step opt imizat ion direct modeling GM( 1, 1) and method to data processing in engineering f ield is put forward, the method of precision inspect ion is introduced. Then, the programming is authorized withMatlab 6. 1 language.Two examples are given, their results are compared with the results of other Grey models, respectively.With this model, the data don??t need to be preprocessed and the generations of accumulation plus and subtract don??t need to be made.The method can be used for model establishing at equal interval, as well as at non- interval. It has high precision and is easy to use.The model is simple and practical, and has a genera-lizing value in the field of CAD.

Key words: grey system, serial weakening, direct model, GM( 1, 1) model, optimization, data processing