A certain pattern recognition method was suggested to optimize the experimental conditions of the sample pretreatment for chemical finger-print experiments. 1H NMR plus Principle component analysis(PCA) were used as the testing and evaluating means,considering that the test samples of finger-print experiments usually consist of multi-components. The data exposed in 1H NMR spectra were wholly involved in PCA to provide the predictable information for the design of the sample pretreatment. With this sleight,w...