To study the seismic behavior of reinforced concrete（RC）frame joints affected by acid rain corro? sion，the artificial climate method was used to simulate the acid rain environment. The accelerated corrosion tests were conducted on eight RC beam-column joint specimens，and then quasi-static tests were carried out. The apparent phenomenon of the specimens corroded by acid rain was observed. The influence of corrosion cycles，axial com? pression ratio and sulfate ion concentration on the failure characteristics，hysteretic behavior，shear performance and shear capacity of the RC frame beam-column joints were analyzed. On this basis，the damage index was intro? duced，and the parameters of damage model were determined. Then，the damage evolution of the specimens during the loading process was revealed quantitatively. The results of test and analysis show that，aggregate exposure，crys? tal precipitation and eroded holes appear on the specimens due to acid rain corrosion，but the maximum shear force of corroded joint core area is still less than the threshold of the seismic shear capacity calculated by the current Chi? nese standard. With the increase of corrosion cycles and sulfate ion concentration，the bending cracks at the beam and the shear cracks at the core area appear earlier and develop rapidly，and the bearing capacity，deformation ca? pacity，energy dissipation capacity decreased gradually，while the shear proportion and damage development rate in? crease continuously. For the specimen with a larger axial compression ratio，the bearing capacity is relatively large， while the deformation capacity is poor，and the shear proportion and damage development rate increase are large.