The paper analyses the belief of folk customs of a particular Mongolian village and expound the process of the formation,the existence as well as the inheritance of Mongolian folk customs in a specific,providing a further discussion.about the social function and the value of this Mongolian folk belief. The overall thread of thought is to single out a living sample with the belief of folk customs and make an analysis of its ceremony by placing it into the changing social environment. By restoring the history of belief of folk customs, the paper attempts to explore the basic features of Mongolian life regarding this belief of folk customs.Meanwhile,Zhu Laqin Villege belief of folk customs is divided into three parts as oral language system (legend), habits (ceremony or rituals) and psychological response (worship). Based on the legend about the oral language system, a series of phenomena concerning the belief of folk customs are exposed so as to display the complete operation of this system. As for the concret e study, a specific Mongolian village is concerned and a series of problems are involved such as : How does it come into existence ? What functions does it have ? What are the structural character is tics ? How do the activities go and why did they get stopped and how did they get resumed in a changing world ? How is its formation and inheritance ? What are the social functions and value about the belief of folk customs ? Why is it necessary to use case study on this issue ? The paper consists of seven parts. The Forward mainly deals with the methodology, the theory, the materials and the achievements of the case study on the folk customs of a Mongolian village. Chapter One introduces a sample village ; Chapter Two depicts the study on the legend of a princess ; Chapter Three, the study on the ceremony for the princess ; Chapter Four, the study on other ceremonies including for Aobao, Sacred Tree (shen shu), Jiu Shenmiao, Ancestors, Gods in charge of Fire and the Sky ; Chapter Five, the formation and transmission of the folk customs in Zhu Laqin village and the last part comes to the conclusion.
