The change of livelihoods is an important part among overall social changes. This paper describes the means of livelihood changes through the field research of the changes of rural livelihoods and conducts in-depth analysis of the dynamic mechanism of livelihoods' changes with the example of D County, Hebei Province. The changes of livelihoods lead to instability in family income, interpersonal utilitarian, the irrational situation of social mobility, as well as the odd issue of the indifference of social acquaintances. The way to actively seek to make farmers adapt rationally to livelihoods to changes is directly related to the new rural construction and the social stability.