In this study, a gold (Au) nanomesh layer was manufactured on an ITO-coated glass substrate at room temperature. The Au nanomesh was used to induce surface plasmon resonance (SPR) to enhance the photocurrent of a polymer solar cell. The Au nanomesh was manufactured by lift-off on closely packed PS nanospheres (diameter ∼50nm; density ∼10 10 /cm 2 ). The PS nanospheres were fabricated by modified block copolymer nano-patterning on ITO. A transmittance–reflection–absorbance spectrum was used to explore the induced surface plasmon. An extinction peak was observed at ∼580nm indicate the possibility of Au nanomesh induced surface plasmon resonance. The short-circuit current density of the polymer solar cell was enhanced from 7.02 to 14.2mA/cm 2 by the addition of Au nanomesh. Consequently, the power conversion efficiency enhanced from 1.9% to 3.2%. By the normalized input photon-to-current conversion efficiency (IPCE) measurement, enhanced photocurrent conversion efficiency at approximately 580nm was observed that coincided with the extinction spectrum, indicating that the surface plasmon enhanced the photocurrent.