Engineered　cementitious　composite　(ECC)　possesses　excellent　ductility　resulting　from　the　presence　of　organic　fiber,　however,　the　ECC　exhibits　a　significant　shrinkage　performance,　which　is　likely　to　induce　cracking　under　the　constrained　condition　in　practical　engineering.　In　this　paper,　the　effect　of　fiber　on　the　shrinkage　behavior　of　ECC　was　investigated　based　on　the　steel　ring　with　different　constraints,　and　the　cracking　risks　of　ECC　under　constraints　were　discussed.　The　experimental　results　show　that　increasing　fiber　content　and　length　in　ECC　are　conducive　to　the　splitting　tensile　strength,　the　28　days　strength　are　improved　by　36　%　and　16　%　as　the　content　and　length　of　PVA　fiber　are　increased　from　0　%　to　2　%　and　6　mm　to　12　mm,　respectively.　And　the　addition　of　PE　fiber　is　helpful　to　the　strength　development,　the　strength　is　about　15　%　higher　than　those　with　PP　and　PVA　fiber.　Under　the　uniform　constraint,　the　fiber　content　has　a　significant　impact　on　the　shrinkage　development　of　ECC,　and　the　cracking　is　observed　in　the　specimens　with　insufficient　fiber　content.　However,　the　cracking　is　likely　to　be　induced　in　the　case　of　non-uniform　constraint,　and　the　reduction　of　fiber　content　and　length　accelerates　the　cracking　age　while　the　introduction　of　PVA　fiber　delays　the　cracking,　the　cracking　age　of　ECC　with　2　%　PVA　fiber　content　is　28.2　d,　being　later　than　those　of　ECC　with　PP　and　PE　fiber,　which　is　related　to　the　moderate　limited　elongation　and　rough　surface.　Due　to　the　ECC　ductility　and　constraint,　the　traditional　cracking　risk　criterion　Theta　CR　is　not　suitable　for　the　ECC　under　uniform　constraint,　Additionally,　although　the　proposed　eta　is　suitable　for　the　cracking　risk　evaluation　of　ECC　under　non-uniform　constraint,　the　cracking　tendency　is　still　not　able　to　be　predicted.　Therefore,　the　constraint　condition　and　material　properties　should　be　considered　in　the　evaluation　of　ECC　cracking　risk.