A sodium-concrete reaction facility with a test chamber of 0.226㎥($Phi$0.6m$ imes$H0.8m) was constructed to carry out experiments of sodium-concrete reaction which might take place in sodium metal fast-breeder reactor Utilizing this facility, several experiments were conducted to closely examine the characteristics of sodium-concrete reactions under different conditions : Sodium mass : 100, 250g ; Sodium temperature : 450, 550, $650^{circ}C$ ; Concrete age = 30, 45, 50, 90days. Our experiments show that the amount of the H2 generated by sodium-concrete reaction has increased up to its flammable range as the amount of spilled sodium and its temperature have increased. The maximum hydrogen concentration was 31mo1% at the concrete age of 30days, sodium temperature : 55$0^{circ}C$, and sodium mass : 250g. The major components of sodium-concrete reaction products were also determined as Na$_2$SiO$_3$ and NaAlO$_2$.