[Objective] The paper was to study the changes of protein content and component in leaves of Toona Sinensis under low-temperature stress. [Method] Potted experiment was adopted, and SDS-PAGE electrophoresis was also used to analyze the dynamic changes of protein in T. Sinensis leaves. [Result] Low temperature stress could change the content and component in leaves of T. Sinensis, but different provenances had different performance under different temperatures, so did the same provenance under different stress periods. SDS-PAGE electrophoresis results indicated that the change law of provenances of Xixia of Henan and Nanjing of Jiangsu with stronger cold resistance was similar, showing the change trend of “increase-decrease-increase”. Protein was greatly expressed after stress for 1 d, the color of band became darker; the content gradually decreased in the following second and third day, and the color of bands was lighter; the content began to increase at the forth day. Two provenances induced the specific proteins with molecular weights of 27.6 and 22.5 kD, respectively. The soluble protein content of provenance of Xiapu of Fujian with relatively weak cold resistance was gradually increased, but no new protein bands were induced. The changes of protein band color of various provenances in SDS-PAGE electrophoresis was basically consistent with the changes of protein content, the provenance with stronger cold resistance could induce the production of specific proteins. [Conclusion] The study provided theoretical basis for under the molecular mechanism of plant cold resistance, which had great significance in theory and practice.