Retrofitting of the structure is better alternative instead of whole replacement of structure. Retrofitting by using Carbon fiber reinforced polymer (CFRP) and Aramid fiber reinforced polymer (AFRP) has been increasing interest. Recently, CFRP and AFRP are being used for steel structures also. The purposes of using CFRP and AFRP materials are i) High strength to weight ratio ii) Better durability in worst environment. CFRP and AFRP bonded structures have less cost as compared to cost of replacement of structure. It increases load carrying capacity and improves stiffness and buckling behavior of structure. In this paper study of behavior of hollow square section strengthened with carbon fiber reinforced polymer and aramid fiber reinforced polymer are carried out. Square hollow sections were used as columns and CFRP and AFRP as a strengthening material. CFRP and AFRP bonded columns with change in width of CFRP and AFRP strips and various numbers in layers were tested. These column sections were analyzed using ANSYS 14.5. In comparison of intact section and CFRP and AFRP bonded sections, load carrying capacity of CFRP and AFRP bonded sections were increased. Then it comparing by experimental work to be done.