Definition of a leader has been defined by different people with different ways. Thus, what is the concrete definition of the word “leader”? Each of us will have our own different answer. In dictionary, the word “leader” has been defined as a person who influences a group of people. For me, leader is a captain of a group or a person who able to organise, manage, make decision, analyse, negotiate, indentify source of problem, solve problem, and train junior. A qualified leader at least must have good leadership and good relationship to ensure that his group is working well and smooth. Leadership is very important for a qualified leader, because leadership affects the performance of a team, an excellent leadership will improve a team performance. The relationship between leader and his team members is quite important for a qualified leader as well, because a good relationship will help the leader to communicate to his team members easily and send right massage to his team members. In fact, a team leader takes on the leadership role in his team. He or she has to direct, supervise, guide and instruct the team. These are the duties of a team leader to promote unity of his team and to ensure that his team to function as good as possible. As a leader, he or she inspires the team to action in anytime. Therefore, the team leader is the line of communication from upper management to team members. The leader completes his team’s quality and advises his team members if there are rooms for improvement.