One-dimensional (1D) mesoporous ternary Co-Ni-Mn oxide nanowires (CNMO NWs) have been controllably fabricated via a facile yet scalable template-free strategy involving a green hydrothermal route coupled with the following calcination. The composition of the reaction solvent system, i.e., the volume ratio of the ethylene glycol and deionized water, plays a significant role in tuning the specific morphologies and microstructures of the final CNMO products. The as-derived ID CNMO NWs are constructed with numerous nanoparticle subunits with the size of approximate to 5-10 nm, and possess lots of interparticle mesopores ranged from 2 to 6 nm. The well-defined mesoporous CNMO NWs apparently have appealing structural advantages, such as fast and convenient electron and ion transport, sufficient redox electrochemical centers with multiple valences, and large electroactive surface area. As a result, the as-fabricated mesoporous CNMO NWs manifest exceptional pesudocapacitance and excellent cycling stability at high rates when evaluated as a striking low-cost electrode for next-generation electrochemical capacitors.