Based on an analysis of fieldwork data collected by the authors from 80 households in the Shapo Village of Shuicheng County in Guizhou Province, the phenomenon of differentiation between behaviors of households who own different resources has been found. The differentiation is adaptable to resources, environment and structure of society and economy up against households. The paper has revealed the main characteristics of employment structure, employment behaviors in both agricultural and nonagricultural sectors and has explained the causes. The results show that factors such as household registration system, low economic accumulation, limited knowledge and simple technology restrict the farmers to be employed by nonagricultural sectors; and household registration constitutes the greatest institutional barrier constraining the migration of rural workers. Because of the low input and output agricultural production mode, households have few accumulation generally, helping the households break out the greatest institutional barrier of registration system to migrate. But owing to the limited knowledge and simple technology, the farmers can not get stable job and incomes, which pull them back home, most of the farmers cannot but choose part time work in nonagricultural sectors. Part time work in nonagricultural sectors can improve the farmers' living standard to a certain degree, which however can contribute little to the optimization of the rural resources, as well as the rural social and economic development. Finally some feasible suggestions are put forwards, i.e.,control the amount of population and increase investment of education; to establish uniform system of social security; and to strengthen rural infrastructure construcion.