The spectral imaging technology is applied to active constituent detection of traditional Chinese medicines (TCMs) in-vivo. The active constituent of cortex phellodendri chinensis-berberine is detected in-vivo by the home-made liquid crystal spectral imaging system. The central wavelength of the light source is 254 nm and the selected spectral range is from 480 nm to 700 nm. A series of fluorescent images called spectrum cube are obtained. After analyzing the spectrum section of the spectrum cube of the samples, a high-pass filter is designed based on the spectrum section of berberine, which is the standared sample supplied by national institute for fhe control of pharmaceutical and biological products. The characteristic spectra of the samples are got. The characteristic spectra of cortex phellodendri chinensis from eight sources are compared, as well as that and wampee. The results show that the spectral imaging technology is available to detect TCMs rapidly, accurately, in-vivo, and none-destructively.