Concrete　cover　cracking　induced　by　corrosion　of　steel　reinforcement　is　a　major　influencing　factor　for　durability　and　service-ability　of　reinforced　concrete　(RC)　structures.　Here　in　the　study,　the　influence　of　concrete　meso-structure　on　the　failure　pattern　of　concrete　cover　is　accounted　for.　At　the　meso-scale,　the　concrete　is　assumed　to　be　a　three-phase　composite　composed　of　aggregate,　mortar　matrix　and　the　interfacial　transition　zone　(ITZ).　A　random　aggregate　structure　of　concrete　is　established　for　the　study　on　the　mechanical　behavior　of　cover　subjected　to　corrosion　expansion　of　steel　reinforcement.　In　the　simulations,　the　plasticity　damaged　model　is　used　to　describe　the　mechanical　behavior　of　the　mortar　matrix　and　the　ITZ,　and　it　is　assumed　that　the　corrosion　of　steel　reinforcement　is　uniform.　Based　on　the　above　assumptions,　the　cracking　of　concrete　cover　due　to　steel　reinforcement　corrosion　is　numerically　simulated.　The　failure　patterns　obtained　from　the　macro-scale　homogeneous　model　and　the　present　meso-scale　heterogeneous　model　are　compared.　The　effects　of　the　ratio　of　cover　thickness　and　reinforcement　diameter　(i.　e.　c/d),　the　position　of　the　steel　reinforcement　(i.e.,　the　middle　and　corner　zones)　and　the　concrete　tensile　strength　on　the　steel　corrosion　level　when　the　concrete　cover　cracks　are　investigated.　Finally,　some　useful　conclusions　are　drawn.　©　2015,　Editorial　Office　of　Chinese　Journal　of　Computational　Mechanics.　All　right　reserved.