Chloride ion permeability of low shrinkage engineered cementitious composites(LSECC) was studied. Specimens of non cracking LSECC with different water binder ratios, molding methods and curing ages and cracking LSECC induced by 4 point bending test controlled by deformation in tensile zone were prepared. Chloride ion permeability was evaluated by both ASTM C1202 and NEL methods. Results show that chloride ion permeability of non cracking LSECC is decreased by utilizing lower water binder ratio, extrusion method and longer curing age. Chloride ion permeability of cracking LSECC can be divided into two stages：before and after matrix cracking. Number and width of cracks are decreased by lowering water binder ratio, and similar conclusion can be drawn with the reduction rate of chloride ion penetration. ASTM C1202method is more sensitive to chloride ion permeability of cracking LSECC than NEL method.