The stress corrosion cracking (SCC) behaviors of 2A12 aluminum alloy after annealing treatment were studied by slow strain rate testing (SSRT), electrochemical polarization measurement, scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and transmission electron microscopy (TEM). Various concentrations of NaCl, H2SO4 and HCl aqueous solution were prepared to act as the corrosive solution. The experimental results show that regarding the SCC, 2A12 alloy performs best in NaCl solution but worst in HCl solution and intermediately between the above mentioned two cases in H2SO4 solution. For the SSRT carried out in room temperature, there is a higher decrease in elongation without large strength loss for the alloy immersed in NaCl solution. With the test conducted in H2SO4 solution, there is a higher strength loss and a relatively less loss of elongation compared to the one immersed in NaCl solution. With the test conducted in HCl solution, there is a relativel level loss of strength and elongation compared to either result carried out in NaCl solution or H2SO4 solution.