Abstract: The electrodeposition technology was used to in situ synthesize NiO-FeS nanocomposites on nickel foam (NF) substrate to improve the efficiency of electrocatalytic water splitting. SEM, TEM, EDS and XPS characterizations were adopted to explore the surface morphology and chemical composition of the as-obtained materials. It was demonstrated that the nanocomposites mainly consisted of FeS and NiO with an obvious two-dimensional sheet-like structure and a well-defined heterojunction was formed between the two constituents. The NiO-FeS@NF nanocomposites were directly used as the working electrode for electrocatalytic oxygen evolution reactions (OER) to enhance the catalytic activity. The two-dimensional structure could provide a large surface area and abundant active sites, which facilitated the electron transfer process at the NiO-FeS interface. This study may offer a convenient and inexpensive access to the fabrication of efficient nanocatalysts.