Empirical data show that most of the degree distribution of airline networks assume a double power law.In this work,firstly,we assume cities as sites,flight between two cities as an edge between two sites,and build a dynamic evolution model for airline networks by improving the BA model,in which the conception of attractiveness plays a decisive role in the course of evolution of the networks.To this end,we discuss whether the attractiveness depends on the site label s or not separately,finally we obtain analytic degree distribution.As a result,if the attractiveness of a site is independent of the degree distribution of sites,which will follow the double power law,otherwise,it will be scale-free.Moreover,degree distribution depends on the parameters of the models,and some parameters are more sensitive than others.