History of Science and Engineering Annotation << Back To the History of Becoming of Differential Geometry: L. Euler’s Researches of The Theory of Spatial Curves I.V. Ignatushina There is a clever presentation the ways of L. Euler’s for research of spatial curves. Considerably Euler has applied the majority of means of the infinitesimal analysis to resolve one of the typical geometrical question. The submitted material is an illustration of process of formation of differential geometry in XVIII century. Key words: differential geometry; Leonhard Euler; the theory of spatial curves; history of mathematics.