The research on the attachment to God initiated by Kirkpatrick tends to use quantitative research methods, that is, to use the Attachment to God Inventory(AGI) or experiment methods to study. Taking into account that prayer exists primarily as a process or a dialogue, it should be more suitable for qualitative research. The study of prayer and the attachment to God in China is still at an early stage. In this study, qualitative research methods were used to explore the formation and development of an attachment to God during the process of prayer by Christians. The researchers, as non-believers, were external to the religious world of the participants; they used an intensity sampling method and a comprehensive sampling strategy to gain study participants. The sample was composed of 14 Christians(7 men and 7 women) who were formally baptized(between 2 years and 32 years ago). Researchers conducted in-depth interviews with each of the participants. From a grounded theory base, preliminary analysis, generic analysis and theoretical construction of the collected data were made. Participants inspection and non-participants inspection were adapted to verify the research results’ validity. The following conclusions were drawn: Prayer is an important channel for Christians to communicate with God. Based on the prerequisite of "faith", Christians expose their minds to God, make psychological appeals to God, and gradually establish an intimate relationship with God. This provides a context in which the attachment to God can be activated. In turn, the increase in intimacy with God promotes the degree of Christians’ faith in God. Difficulties in real life provide incentives for Christians to pray and thus promote the development of their attachment to God. Christian prayer usually goes through three stages, and eventually forms a "God-centered" coping schema. During this process, the concept of "God" is increasingly embedded into the Christian self, the psychological representations of "God" are constantly strengthened, while the psychological representations of "self" are weakened. Eventually Christians enter a state of "no me". This study made a comparison between the attachment to God and interpersonal attachment and an exploration to the internal working model of the attachment to GOD during the process of prayer by Christian. On one hand, the study enriches and promotes the development of research on religious psychology in China, on the other hand, it provides a path to guide people’s religious behavior. The results of this study are considered to be able to contribute to social harmony and stability, and to promote people to live and work in peace.