The purpose of this book is to illustrate step by step the design of the Composite Wing Structure of the external wing for an Unmanned Aerial Vehicle- UAV. The design is conducted using software tools for Finite Element Analysis, such as, NASTRAN and ANSYS to find the structural integrity limits for composite materials and fittings. Data for this study were obtained from AEROTECH Research Group at Universidad de San Buenaventura, Bogota, Colombia. Finite Element Methods are used in order to evaluate the static strength, maximum stresses and buckling behavior of composite structures. Sections, such as spars, webs and caps, ribs, skins and stringers assemblies are analyzed to get the best strength to weight ratio and its manufacturing procedure. The analysis should be especially useful to professionals in Aerospace and Mechanical Engineering, or anyone else who may be considering utilizing design methodologies to analyze structural configurations of composite structures using Finite Element Methods and the conceptual manufacturing procedures for further fabrication.