The Li Su people in the northwest of Yunnan province chose to believe Christianity from the 1990 s, an inevitable choice for the ethnic living in the atomized and fragmented social structure, facing discrimination of the surrounding people and the multiple pressures of reproduction of population and material goods. Based on investigation to the process of conversion to Christianity of the Lisu people in a township, the article points out that the mode of "marriage–family-landminority" is the network of Christianity spreading to the Lisu society, it can be used to explain why Christianity spreads in the Lisu society with ethnic characteristic, which differs from the Christianity’s growth in the Han society with characteristics of lineage.