Life expectancy is a comprehensive measurement of mortality,which essentially has a close and interactive relationship with mortality by age.The decomposition of life expectancy difference is a useful tool to study the regular pattern in changes of death mode.Pollard and Arriaga proposed two decomposition methods to explain life expectancy differences.This paper will introduce these two methods and apply them to China’s Life Table of 1990 and 2008.In addition,we compare the characteristics of the two decomposition methods,and provide recommendations for their applications.