Vergil's poems are exceptionally complex and polyhedral. An understanding and interpretation of the deeper meaning are further hindered by the fluency of the surface structure. A structural analysis is an excellent way to penetrate to the deeper levels of a poem. Since studies on the symbolic numbers and the golden ratio in Vergil's work were published in the first half of the 20th century, it became a sensitive subject among critics. This dissertation tries to give an answer between the most extreme viewpoints. The hypothesis of the dissertation is that the golden ratio (1: (<font face>v</font>5-1)/2) plays an important part in the structures of both the Eclogae book and in some of the individual poems. The first chapter is concerned with the basic structural patterns in the Eclogues. It argues that the asymmetric division of a poem or book of poems is not made by chance, but the same accuracy shows in the ratios of one part to another, than the more common symmetrical structure. The chapter looks at the recessed panel, parallel patterns and asymmetric divisions, discusses their functions in poetry and touches on textual clues to the division of poems. The golden ratio is defined in the second chapter. Its frequency in nature is shown and the ancient peoples' knowledge of its properties and use in architecture and plastic arts is discussed. The structure of the Eclogues and the Eclogue book is enunciated in chapters 4 and 5. The golden ratios present in some of the poems are discussed, placed in the perspective of the whole book and their functions in the work explained. The structures in the poems themselves recur in the structure of the book and chapter 5 re-evaluate the structural model of the Eclogues already proposed. With the supplementary numerical data a new structural model is proposed that would better explain the various relationships between the poems and groups of poems.