Concrete filled Steel Tube(CFST) is one of solution in high-rise buildings in terms of higher structural stability and an enhanced fire resistance according to higher heat capacity of concrete. Many studies on the CFST have been conducted since 1990 in the Europe, Japan, and Canada. But in Korea, the study on the fire resistance of the CFST is focused on establishment of equation of fire resistance. But the relationships between temperature of perimeter of tube and inner concrete filled at the tube are still uncertain. Therefore, to compare the temperature differences in the tube and concrete filled steel tube, the analysis and fire test with the same model of steel tube and concrete filled steel tube were conducted and got the followings; the temperatures from steel perimeter and concrete filled into the tube and the comparison of the CFST between analysis and fire test showed the very same values during 18 minutes and the temperatures of concrete are not exceed $100^{circ}C$.