Abstract: A chromatographic analyzer is provided for facilitating curve fitting by means of the linear least-square method for a chromatogram that contains a plurality of overlapping peaks. A chromatographic data processor executes fitting processing to each peak in an arbitrary time region having the plurality of peaks of the chromatogram starting from the front side or back of the time region, and the processed peaks are subtracted from the chromatogram in the time region so that the plurality of peaks in the chromatogram can be separated from one another.