The structures of tin nickel alloy and transformation upon heating were investigated. The wearability and corrodibility of them were comparably tested.The results showed plated structures were mainly made up of metastable phases of αNi(M) and NiSn(M),with high tin content forming equilibrium phases of Ni3Sn4 and βSn;metastable phases were transformed to equilibrium phases with heating temperature.Because of homogenous equilibrium phases precipitation, electrodeposited alloy hardness increased; Single phase of NiSn(M) had a bit lower corrodibility than stainless steel in strong oxide medium and its wearability at 400℃ was better than quenching medium carbon steel.