In recent years, aluminum, magnesium and titanium alloys are highly regarded in the aerospace and automotive industries due to their high strength to weight ratio and resistance to corrosion. The main problem of the use of these alloys is their low formability at room temperature. To solve this problem, the metal forming process is done at high temperatures. Since oil’s heat resistant temperature is not more than 300°c, other fluids such as air and nitrogen gas should be used in high temperatures. In this study, blow forming equipment at high temperatures has developed, and changing of AL6063 tubes cross-section from circular to square has investigated experimentally and compared with the results of the experiments at room temperature. After producing square products, thickness distribution, corner’s radius, forming pressure, and effect of pressure time in corner’s radius at different temperatures were compared and the location of bursting was also examined. The results indicated that by increasing temperature, formed radius and pressure time reduces significantly, so that the amount of radius decreases from 19.5 mm in the temperature of 25°c and 154 bar forming pressure, to 5.8 mm in the temperature of 500°c at 11 bar forming pressure. The results showed that by increasing time pressure, which causes to decrease velocity of process, the formed corners has been sharper. By investigating burst of specimens, bursting occurs in the area of converting circular cross section to square one, which has a high deformation and tensile strain.