Delayed fluorescence (DF) spectrum is an efficient method in study transportation of electron in photosynthesis. In the light of the great difference of spectrum characteristic between the experimental results in reference [1] and what have been reported, in this paper the spectrum of DF of chloroplast at different concentrations was studied by using different spectral analysis methods. Experimental results show that the chlorophyll P700 in PS I absorbs the 685 nm component emitted from PS II is increasing as the chloroplast concentration increases, which results in the peak value at 730 nm and nearly disappearance of apex at 685 nm in DF spectrum. Experimental results indicate that the 730 nm component of DF spectrum is the result of re-absorption DF spectrum of 685 nm component, which emitted from PS II as the PSⅠacts on chlorophyll P700. The results in this paper will be of benefit for us for understanding and further study of the mechanism of different components in delayed fluorescence.