Leader's traits evolve over time and are expressed differently under different situations. To capture both the evolution and expression of leader traits, we propose a dynamic model. We argue that the evolution of traits consists of changes in intensity and nature. Based on data on five publicly acknowledged Chinese leaders collected from various sources, we identified three patterns (homological, converse, and composite) by which leader traits evolve. We also discovered that leader's traits can be intrinsic or extrinsic. The intrinsic traits change in intensity; whereas the extrinsic traits are replaced by other traits over time. Factors influencing these changes include both internal (e.g., leaders' own learning and introspection) and external (e.g., major social events and subtle cultural influences). The results of our study show that the traits leaders demonstrated under specific situations are composite in nature, which also supports the notion that traits evolve. Based on our finding, we generated a few propositions for future empirical studies.