Pitting　corrosion　of　aluminum　alloy　2024-T3　in　NaCl　solution　was　studied　using　electrochemical　noise　technique.　The　spectral　analysis　results　showed　that　the　more　positive　the　values　of　cut-off　frequency　(fc),　the　slope　of　high-frequency　linear　part　of　SPD(　k)　and　white　noise　level(　W)　are,　the　more　easily　the　pit　initiates,　but　none　of　them　can　be　used　to　depict　the　corrosion　process　individually.　Two　new　parameters(　SE　and　SG)　were　derived　by　using　dimensional　analysis　method,　and　the　value　of　SE　characterize　the　severity　of　pitting　of　corroding　material.　While　the　meaning　of　the　other　parameter(SG)　remains　for　further　investigation.