Photosynthesis is one of the main processes involved in plant growth and development. This process is sensitive to environmental stressors, including cadmium environment contamination. Therefore, this study investigated, among other things, the effect of cadmium on the fluorescence of photosynthesis parameters, chlorophyll fluorescence; moreover, as the chlorophyll and carotenoids contents were measured. The toxic effect of cadmium on the growth, development, and photosynthesis process was confirmed. In order to study the cadmium binding mechanism by the plant, the first step was to verify the cadmium quantification method with ICP-Q-MS. It was shown that selecting the m/z spectral line: 114; gave a lower background and higher sensitivity for the determination of cadmium in a solution than when selecting 112. The limits of detection and quantification are 2.2 and 7.5 ng/L, respectively, and the method is linear in the investigated concentration range (range up to 100 μg/L). The method of the microwave assisted mineralization in the preparation of a plant sample was shown to meet the requirements of accuracy (recovery with the certified reference material 98%) and repeatability (0.13% in five repetitions). Root and shoot samples of pea were examined and the accumulation of cadmium especially in the roots was found, which proves the excludable properties of the plant.