Nodular corrosion a local corrosion occurring on the surface of zirconium alloys usually in boiling water reactors (BWR), directly affects service life of the zirconium cladding and threatens the safety of reactors. The occurrence, propagation morphology of nodules and other characteristics of nodular corrosion, are summarized. The commonly accepted models of nodular corrosion include the hydrogen accumulation model of KUWAE[ref] and nucleation & growth model of ZHOU[ref]. Main driving factors include surface condition, heat treatment, alloying composition, presence of second phase particles and irradiation. Processes to suppress nodular corrosion are presented in the present paper, for instance: increasing the Fe+Cr content, decreasing the Sn content, decreasing the annealing time and temperature, improving the surface finish. But, the most effective means of improving nodular corrosion resistance is to use a new zirconium alloy containing niobium.