Objective：To develop a new quantitative method without calibration set for near-infrared spectroscopy (NIR). Methods: The new calibration-free NIR method was based on a spectrum of the sample and a spectrum of the mixture. The similar intervals between the spectra of the sample and the mixture were obtained through second derivation, differential spectra and calculation of similarity. Then statistical quantitative analysis was performed. Results: The contents of 3 components in 3 samples were determined with the new method; the average recovery was 100.9% and the relative standard deviation was 6.1% (n=9). Conclusion: Satisfactory results can be obtained by this new method without traditional calibration set. The new method provides an alternative for the quantitative analysis in NIRs and has a promising future.