Abstract: 【Purpose/significance】Judge the structure, evolution and relationship of Metrology Science through the constituent ele⁃ments of Metrology discipline.【Method/process】Quantification has become the basic feature of today's social development. A series of Metrology disciplines have emerged around metrology activities,forming a metrology discipline pedigree. Through literature investiga⁃tion,comparative analysis and logical thinking,the metrology discipline is divided into natural (material) metrology discipline group and social (information) metrology discipline group.【Result/conclusion】the metrology discipline pedigree focuses on the quantitative char⁃acteristics of natural phenomena (material) and social phenomena (information),forming two metrology discipline groups,each contain⁃
ing a series of branch disciplines. The structural dimensions of Metrology branches are composed of three core elements: measurement unit,measurement standard and method,and three basic elements: measurement field,measurement object and measurement character⁃istics. With the change of core elements and basic elements,different metrology branches have emerged.【Innovation/limitation】the re⁃lationship between metrology disciplines is very complex,and there are a series of new research branches that need to be explored. It is
necessary to further excavate and analyze the constituent elements of disciplines and their relationships.