Abstract: In order to investigate the characteristics of tensile and shear strength of front fillet welded joint post-high-temperatures, the tension tests for double strapped front fillet welded joint were conducted after cooling down from different high temperatures.The tests indicate that specimens are fractured at the middle of steel plate as the maximum temperature undergone below 500℃ and brittle fractured at the throat of fillet weld as the maximum temperatures undergone above 500℃.The maximum temperature undergone and the cooling pattern are major factors influencing tensile and shear strength of front fillet welded joint post-high-temperatures.Based on the experimental results, this paper proposes the calculation formulas of tensile and shear strength of front fillet welded joint post-high-temperatures.The conclusions supply references for evaluation damage and reinforcement of steel structure post fire.