Just from the day that people started to live by group, the issue of management appeared. Among the different elements in these topics, the function of leader is highly focused on, and there is always a debate about the time of their tenure of the office--whether it is appropriate for all the leaders, in the field of education, business, government, to be required to step dowmn after five years. As for me, i think the tenure of a leader should be determined by the characteristic of different field and the leader's quality. Admittedly, there is an obvious disadvantage in the political field, if the leader is on his/her position for a long time, that is, without the worry of losing power, it is easy for the leader to generate rent-seeking bureaucracy, so that the base of democracy will be entirely ruined. Even not the same person, but a same party can also bring the disaster to a country because of the one-party system, such as Soviet Union. The highly concentrated political system eventually made the government official turned into a class full of privilege. During the depression period, comparing to the  common people lacking the basic living condition, the members of the party in power could still enjoy their luxury life. Therefore, we can see that in the political field, it is very necessary to require those in power to step down after five years. The policy written in the constitution of all the democratic countries claims that the top leaders should be changed in every four or five years, which is one of the best ways to avoid the absolute corruption caused by the absolute power. However, in the business field, the situation is more complicated. We cannot arbitrarily determine the tenure of the leader simply by the span of time. It is often said that the new leader, with the new idea about the developing trend of the industry, has the strong willing to renovate, thus, they will imbue the fresh thinking to the management to make a change in the company. For example, Jack Welch, a temporary master of management, became the most young CEO of GE in his 45 years old. At that moment, he also started a fight with the rigid hierarchy in GE. He firstly eliminated 4 management levels so that the order can worked efficiently, and then cut down 25% sub-enterprises to make resource more concentrated and made more profit. Not for a long time, GE returned to one of the greatest companies in the world and Jack Welch also won the reputation all over the world. On the other hand, we can see some companies, having the gene of the leaders who founded the company, which are hard for others to manage, especially the IT companies. Because in this industry, the visionary talent is extremely crucial for its success, the MS, Apple, Google, ect, are the right cases to illustrate this. Bill Gates made the miracle of MS through window operation system, however, when he resigned from the board, the MS leaded by Steve Ballmer has little inspiration for innovation. Apple company form a fanatic buying fashion by Steve Jobs, who built a strong engine to reject mediocre and create something unusual for this company. Now as he left this world, people started to predict Apple will finally become an ordinary IT company. The cased mentioned above just pass us a signal that some companies are just the ones only the genius founders can build and develop. In these cases, the management time cannot be strictly defined by 5 years. To sum up, the management should abide by the rule of democracy and equity, and the leader should have the required and matching personalities, such as vision, passion, create,  management skill and so on. The aim of management is to make reasonable use of all the resources--intelligence, materials, fund--to create more and more richful outcome for the wonderful future of all human beings, thus, besides the time of  tenure, we should have a comprehensive thinking about the topic of management. That's why i don't totally agree with this statement.