Due to the growing population and increasing needs, the need for a wide range of resources and vast amounts of material is highly felt. The combination of wood and steel is a new composite which is used all around the world. Each of them have their own advantages and disadvantages as follows: Wood is a reproducible, easy to use, lightweight material that reduces energy consumption and has higher resistance in comparison to concrete and steel. However it includes disadvantages like high moisture absorption, low resistance to fire, insect attack, and so on. Steel is a material with high resistance, durability and high ductility. Its disadvantages would be like its low resistance to high temperature, corrosion against external factors, local buckling, etc. The combination of these materials always improve their properties, for instance the composite cross section made of steel and wood is harder and more ductile. The main purpose of this thesis is to investigate the behavior of confined timber columns which are contain of wood, rectangular steel hollow sections and fiber reinforced polymer sheets. Several tests were conducted on different specimens and the impact of each materials was studied on the structural behavior of these members under axial compression. The timber infill was found to significantly improve the ultimate load capacity and by preventing local inward buckling. The results show that timbers confined with CFRP sheets have higher ultimate load capacity and ductility.