Location problem is an ancient problem with more than one hundred years of development history. This problem can be divided into two basic types：The one is continuous and the other is discrete. The former is also known as the planar location problem.Its research methods include the calculus and mathematical programming aspects;the latter is also known as the network location problem. The research methods are combined analysis.This is a problem in our life--the supermarket location. We can get the optimal solution from a variety of possible solutions.