Objectives To understand the vaccination situation of left-behind children in rural areas,provide the evidence for developing vaccination strategies for left-behind children.Methods The counties with population over 1,000,000 were selected from Anhui and Sichuan provinces respectively to conduct survery to the children who were born between the year 2003 and 2006,and had registration on vaccination book(card).Results The proportion of left-behind and outflow children are 17.94% and 6.05% respectively.The information about the children’s parents going out most came from village doctors. The proportion of the parents going out after children born was 51.60%,staying outside for more than 10 months was 78.50%. 67.97% pareets came back home during the spring festival,35.43% left-behind children went out with their parents.Conclusion Although the number of outflow children was smaller than the left-behind children,it was easy to develop immunization gap. It is the difficult part of management on EPI to migraut children. The information aboat the children’s parents going out mostly came from village doctors. It is impotant to mobilize the enthusiasm of doctors.It is especially essential that we should propagandize to the people with vaccination knowledge to the pareets came back home during spring festival.