An iron-based sprayed coating for coating a bore inner surface of a cylinder block for an internal combustion engine. A coating surface contains pits, its pit amount is within a range of 0.01% to 2.1%, and an average roughness Ra of this coating surface is within a range of 0.01 µm to 0.15 µm. The cylinder block for an internal combustion engine includes a bore having this iron-based sprayed coating on its inner surface, and a cylinder block body having the bore. A sliding mechanism for an internal combustion engine includes this cylinder block for an internal combustion engine and a piston slidable with the bore of this cylinder block. The piston has a piston ring, and the piston ring has a chromium coating, a chromium nitride coating, or a diamond-like carbon coating at a sliding part with the bore.