The purpose of this dissertation is to describe the use of composite materials in aircraft constructions. The types and characteristics of composite materials are described because of their great use in aviation industry. The entire theory of composite materials themselves is united, from their division and sort of used materials, to the way they are produced. Composite materials with polymer matrix are described, same as their use and the way which makes them the most usable composite materials in aviation industry. The second level of classification refers to the reinforcement form which describes fiber - reinforced composite materials. Composite materials with polymer matrix reinforced with fiberglass, aramid and carbon fiber are the most used composite materials in aircraft constructions. The reason of their wide use is their excellent performance. Each type of composite material is characterized by its own advantages and disadvantages such as: high strength toughness and hardness, low weight, long duration, high temperature resistance etc. These mentioned advantages are very important in aircraft constructions because they truly improve the chatacteristics of the construction same as they compete previous, so called, conventional materials. These improved properties of composite materials are used in construction of Airbus A380 and Boeing 787 Dreamliner which presents the great development of the safest and the most efficient aircrafts.