  We consider $R^4$ corrections to the holographic Schwinger effect in an AdS
black hole background and a confining D3-brane background. The potential
between a test particle pair are performed for both backgrounds. We find there
is no potential barrier in the critical electric field, which means that the
system becomes catastrophically unstable. It is shown that for both backgrounds
increasing the inverse 't Hooft coupling parameter $1/\lambda$ enhances the
Schwinger effect. We also discuss the possible relation between the Schwinger
effect and the viscosity-entropy ratio $\eta/s$ in strong coupling.
