Rice pollution by cadmium in China is becoming a crucial problem in food safety. It is of great importance for the future design of cadmium-removal strategy by studying the binding behaviors of cadmium to different fractions of rice proteins (RPs). In this study, the thermodynamics and kinetics involved in the bindings of cadmium to four different RP fractions, i.e., glutelin, prolamin, globulin and enzyme-extracted proteins, were investigated. The results showed that cadmium was readily bound to each fraction of RPs, and the equilibrium was attained within 30 min. Of all the protein fractions, prolamin obtained the highest binding capacity with a binding q of 23.78 mg/g, whereas globulin had the lowest binding of 3.64 mg/g. The bindings of cadmium to all of the protein fractions belonged to a quasi-second-order kinetics model, and two experimental models, i.e., Freundlich and Langmuir equations were applied to the reactions. Compared to Freundlich equation, Langmuir equation displayed better fitting of the binding reactions. The fitting parameters ΔG°<0 and ΔH°>0 indicated that the bindings were spontaneous and endothermic. The bindings of cadmium to enzyme-extracted proteins, glutelin, and prolamin had ΔH° of 41.44, 40.32, and 58.75 kJ/mol, respectively, implying that the bindings were due to coordinating, and the binding of cadmium to prolamin was a result of multidentate coordination. The differences in amino acid compositions might attribute to the variations of the bindings. It was found that the sum of glutamic acid and aspartic acid was significantly correlated with the q value with a correlation coefficient of 0.967.