Phytoremediation is a novel method with great potential for site remediation contaminated by heavy metals in future. The cell wall of plant roots is significant to affect the remediation efficiency, for it is related to the multi-interface of heavy metals, pedosphere and plant. The relationship between cell wall of plant and heavy metals is complicated, containing the reaction behavior of physical chemistry, physiology and biochemistry. At present, the spectral technologies are not adequately used to investigate the in-situ response characteristics between cell wall of plant roots and heavy metals. The Calendula officinalis seedlings, the remediation plant in loess, were used as experimental sampleswhile the root characteristic variation was revealed on cell wall. The approaches of X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Raman spectra were applied to analyze the response effect of cell wall to lead/cadmium stress. The results showed: the cell wall appears to be shrinking, and certain amounts of dark particles appear on cell wall. The contents of lead/cadmium increase greatly as shown from XRF, while the representative crystals of lead/cadmium are hardly detected. The absorbance peak at 3 416 cm-1 indicates the coordination effect between lead/cadmium and —OH in FTIR, and the movement of absorbance peaks, from 1 701 to 1 736 cm-1 and 1 593 to 1 618 cm-1, respectively, indicates the different characteristics of protein in cell wall of Calendula officinalis seedlings roots under lead/cadmium stress. The Raman intensity of absorbance peak at 2 960 cm-1 increases under lead/cadmium stress, and it proves the changes on arranging directions of cellulose molecules in cell wall samples. The components (Pectin, protein, cellulose, etc.) and functional groups (—OH, N—H, CO, etc.) of cell wall play an important role in the resistance process of cell wall derived from Calendula officinalis seedlings roots to the stress of lead/cadmium in loess.