We report here a simple approach to the synthesis of highly dispersed Co 3 O 4 nanocubes in higher yield by aqueous precipitation method at low temperatures (70–90°C). The nanosized Co 3 O 4 powders were directly achieved from Co(II) aqueous solution under alkaline and oxidizing conditions. TEM results indicate that the as-prepared Co 3 O 4 has a cubic nanostructure with uniform size of about 20nm and narrow size distribution. Powder X-ray diffraction (XRD) and infrared spectrum (IR) results show that the samples are Co 3 O 4 in spinel structure. The objective Co 3 O 4 nanocubes can be achieved in a wide range of experimental parameters, which can be preserved as stable suspension in distilled water or ethanol for several months with no obvious change. Appropriate reaction time and temperature should be controlled to get better crystallized Co 3 O 4 nanocubes with perfect cubic appearance and good dispersibility. It is essential to achieve cubic-like Co 3 O 4 particles by using ammonia as precipitator. The as-prepared Co 3 O 4 nanocubes, combined with PbO 2 as electrodes, extend improved electrocatalytic activities and decreased oxygen evolution potential in electrochemical reactions, so they can be used as potential electrode materials or electrocatalytic materials. This facile method for the synthesis of Co 3 O 4 nanocubes is a simple and general process without any seed, catalyst, or template, thus it is promising for large-scale and low-cost production of Co 3 O 4 with high-quality.