The great differences of urban definitions of the countries in the world bring many difficulties to their urbanization level's comparison.There also shape different ways of urbanization level's comparison. Through analyses of these problemes, this article tries to find a new method in the hope of raising the scientific levels of comparing urbanization.This article proposes that, on the basis of all the countries urban definitions and depending on the non agricultural population rate,the urban population rate of some countries can be revised by their real level of urbanization,Then the urbanization level of all the countries in the world can be compared. Comparing with other ways of comparison,this method is more comformable to the objective law of urbanization.