Abstract: To investigate the effects of high temperature on the punching shear behavior of reinforced concrete (RC) flat slab structures, in this study, the three-dimensional numerical models were established by using finite element software ABAQUS with consideration of the degradation effects of the mechanical properties of rebars and concrete at high temperature. After the validation of the numerical models, the punching shear behavior of slab-column connections at various fire durations was discussed. Moreover, the effects of reinforcement ratios, slab thicknesses, fire locations and fire area on the punching shear resistance of RC slab-column connections at high temperature were quantified. The results indicate that the slab-column connection undergoing punching shear failure at ambient temperature may fail in flexural-punching at high temperature as the degradation of flexural resistance is much greater than that of punching shear resistance. The punching shear capacity of RC slab-column connection decreases by 18.5% compared with that at ambient temperature when the compression surface of the slab is subjected to local fire for 150 minutes. The load capacity of the slab-column connections decreases more significantly when the tension surface is subjected to fire. Compared with the single-sided fire on the top or bottom of the slab, load capacity of specimens under double-sided fire conditions decreases more significantly. The increase in reinforcement ratio and slab thickness can significantly improve the punching shear resistance of RC slab-column connections at high temperatures, but it will reduce the ductility. When the entire compression surface of the slab is subjected to fire for 150 minutes, the punching shear resistance of RC slab-column connection decreases by 31.1% compared with that of RC slab-column connection under ambient temperature whereas the deformation capacity increases by 13.3 %.