Studies　of　the　influences　of　symmetric　tensile-compressive　low　cyclic　fatigue　behavior　and　dynamic　strain　aging　(DSA)　pre-treatment　on　H68　brass　were　made.　The　results　showed　that　the　cyclic　softening　was　the　main　factor　that　controlled　the　fatigue　life　after　various　pre-treatments.　The　process　of　cyclic　softening　was　believed　to　be　related　to　the　change　of　dislocation　configuration.　TEM　observation　indicated　that　the　uniform　and　stable　dislocation　networks　with　high　density　formed　after　DSA　pre-treatment,　which　increased　the　deformation　stress,　decreased　the　cyclic　strain.　The　cyclic　softening　was　caused　by　the　low　dislocation　density　and　elongated　cell　structure　with　low　energy.