Abstract: This paper deals with the mathematical structure of adjustment computations and is rather an introductory treatise.It is divided into four sections.The first section mainly introduces the nature of some spaces in adjustments.The second section discusses the classification problem of adjustment models.The third section is the focal point in this paper and describes how to use the commutative diagram to write down the main formulas of adjustment directly,the concepts of the two preceding sections being used here.In the last section of this paper some complementary related problems are discussed.