Abstract:The pattern language of public open space in traditional village reveals the traditional ecosophy accumulated by people in the long-term interaction between man and nature under the process of understanding, using and changing the natural landscape and building the settlement. The vocabulary system consists of landscape elements, space unit, and spatial combination and has the function of scale, order, syntax, and meaning with the language grammar. This research focuses on the traditional villages as samples and research on typical space pattern of public open space in traditional village, formed 136 basic patterns and 30 combination patterns, and established the basic vocabulary of public open space in traditional village. Combined with the rural public open space planning and design practice in Jiguanlazi Village in Changbai County, Jilin Province, the research also explores the method and ways to do the human ecosystem planning and design directed by pattern language. Overall, the regularity of the public open space in traditional village is strong, so it has a lot of spatial pattern to learn and imitate, it can support to build the pattern language system with the characteristic of multi-scale and nested structure. At the same time the application of pattern language should be appropriate for landscape environment and feature-driven, all kinds of pattern should be used in the way of "within style but without form" in the planning and design and should be made a corresponding adjustment with local conditions.