Fabrication of highly efficient, sustainable and low-cost nonprecious metal oxide for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is exceedingly challenging and warranted for overall water splitting. Herein, we synthesized cobalt nanoleaves metal-organic framed work (MOF) on nickel foam substrate with uniform growth. After calcination of Co-MOF, molybdenum disulfide nanosheets is grown by a facial hydrothermal method. The as-prepared heterostructure (Co3O4/MoS2) can act as bifunctional electrocatalysts for overall water splitting. Under optimized condition, synthesized Co3O4/MoS2 heterostructure catalyst exhibited excellent catalytic activity for both OER and HER in 1 M KOH solution with a current density of 20 mA cm(-2) at overpotential of 230 mV for OER and 205 mV for HER (@ j = 10 mA cm(-2)) and Tafel slopes of 45 and 98 mV dec(-1), respectively. The superior catalytic activity for both OER and HER arises from the unique heterostructure of Co3O4/MoS2 and the synergistic effects of Co3O4 and MoS2.