In order to analyze seismic behavior of large-scale exterior joints of high-rise precast concrete structures, an experimental study on seismic performances of precast beam to column exterior joints with composite slab was conducted with large full-scale models. The failure pattern, hysteretic characteristic, skeleton curve, displacement ductility and energy dissipation, were analyzed. The results provided some information about the seismic behavior of the joint. However, due to the unique nature of the specimens, several other key parameters could not be varied. Therefore, a numerical joint model taking the bar slippage into consideration was developed based on the OPENSEES software and validated against the results of experimental test, then the parameters analysis was carried out. The study results indicated that the overall seismic performance of cast-in-place joint is almost equal to that of the monolithic specimen.