The concept of limit is due to seek answers to some of the practical problems arising from the precise, mathematical analysis has become the most fundamental and important concept is the basis of calculus. As many important mathematical analysis concepts, such as continuous, derivative so use differential and integral to express the concept of limit, some calculation methods are based on the concept established in the limit, so to grasp the concept of limit Limit of theory and method, analysis of learning mathematics is very important. In this paper, the limit Several Methods for clues to the principle of practical, focused on the ultimate question should pay attention to the problem, and the inverse problem and enter the limits of Function The concept of limit is due to seek answers to some of the practical problems arising from the precise, mathematical analysis has become the most fundamental and important concept is the basis of calculus. As many important mathematical analysis concepts, such as continuous, derivative so use differential and integral to express the concept of limit, some calculation methods are based on the concept established in the limit, so to grasp the concept of limit Limit of theory and method, analysis of learning mathematics is very important. In this paper, the limit Several Methods for clues to the principle of practical, focused on the ultimate question should pay attention to the problem, and the inverse problem and enter the limits of Function