Abstract: Small punch test (SPT) was used to evaluate stress corrosion cracking (SCC) susceptibility of 304L stainless steel, effects of load rate and corrosion medium on evaluating results were studied, and fracture appearance and microstructure evolution of the small punch sample were analysed. The results show that the most appropriate corrosion medium for evaluating stress corrosion cracking susceptibility of 304L stainless steel was mix solution of 1.0 mol·L-1 NaCl and 0.5 mol·L-1 HCl , and the most appropriatin load rate was 3×10-3 mm·min-1, the main fracture of 304L stainless steel sample punch sample was main cleavage frature, and part of quasi-cleavage appearance was observed. The results proved that small punch test was an effective stress corrosion cracking susceptibility evaluation method, and which was fast and nondestructive.