Pareto Principle and The Long Tail are originally statistical theories in the field of economics，which are widely used in commercial marketing and business administration. However，we could apply these two seemingly contradicting theories into student affairs management and practice them. Harnessing The Pareto Principle we could make both ends meet by cultivating outstanding students and improving the performance of less outstanding students. Using The Long Tail，we could help promote full development of one single student and also the development of all students. The Pareto Principle and The Long Tail seem to be contradictory，but as a matter of fact，they make up a dialectical unity. In the management of student affairs，the use of The Pareto Principle and The Long Tail could deepen the depth of ideological and political work in university students and boost its efficacy.