This　paper　experimentally　and　numerically　investigated　the　pull-out　behavior　of　stud　groups　embedded　in　concrete.　Seven　groups　of　pull-out　tests　were　conducted　to　study　the　effect　of　the　arrangement　(i.e.,　single　row　and　matrix)　and　spacing　on　the　pull-out　resistance.　Results　from　the　tests　indicated　that　the　strength　reduction　factor　considering　the　group　effect　increased　with　increasing　spacing　(when　the　ratio　to　depth　is　less　than　3.0)　and　was　influenced　by　the　arrangement.　A　detailed　finite　element　(FE)　model　was　also　developed　and　benchmarked.　The　benchmarked　model　was　then　used　to　investigate:　(i)　the　effect　of　the　concrete　strength　and　the　number,　spacing,　and　arrangement　of　studs,　(ii)　the　force　distribution　among　studs,　and　(iii)　the　tensile　stress　distribution　along　the　concrete　failure　surface.　Results　from　the　FE　analyses　showed　that　the　force　resisted　by　the　external　stud　was　greater　than　the　internal　stud,　and　the　stress　decreased　from　the　stud　head　to　the　concrete　surface.　Finally,　a　new　design　equation　for　estimating　the　pull-out　resistance　of　stud　groups　was　proposed.