Abstract: A rapid and non-destructive method for the determination of total flavonoids in Pteridium aquilinum was proposed by near infrared spectroscopy combined with partial least square method. The 140 samples of Pteridium aquilinum were taken, and their near infrared spectra were collected in the waveband of 4 000-11 500 cm^-1 by Fourier transform near infrared spectrometer. The original spectra obtained were pretreated by the first-order derivative, and the model was established in the waveband of 6 100-7 500 cm^-1 and 5 400-6 000 cm^-1 with principal factor number of 10. It was shown that RMSEC of the quantitative analysis model established with calibration set was 0.078, and R² was 0.991 9. RMSEP of the quantitative analysis model established with varification set was 0.125, and R² was 0.984 1, indicating that the performance of the established model was superior. The completely external validation set samples were analyzed by the quantitative analysis model and UV-Vis spectrophotometry, giving predicted recoveries (percentage ratios of predicted values to determined values) closed to 100%, indicating that the established model had high prediction accuracy, and could be used for the rapid and accurate determination of total flavonoids in Pteridium aquilinum.