The　bandwidth　limitation　in　wideband　audio　communication　systems　degrades　the　subjective　quality　and　naturalness　of　the　reproduced　signals.　In　this　paper,　a　wideband　to　super-wideband　audio　bandwidth　extension　method　was　proposed　by　using　echo　state　network.　The　echo　state　network　is　adopted　to　model　the　mapping　function　between　the　low-and　high-frequency　spectral　coefficients　of　audio　signals,　and　the　temporal　evolution　of　audio　features　is　represented　by　continuously　state　updating　on　the　basis　of　the　recursive　structure　in　the　network,　for　effectively　estimating　the　high-frequency　spectral　envelope.　By　combining　the　high-frequency　fine　spectrum　extended　by　spectral　translation,　the　proposed　method　can　effectively　extend　the　bandwidth　of　wideband　audio　to　super-wideband.　Evaluation　results　show　that　the　proposed　method　upgrades　the　auditory　quality　of　wideband　audio,　and　gains　better　extension　performance　than　the　Gaussian　mixture　model-based　bandwidth　extension　method　in　terms　of　both　static　and　dynamic　distortions　for　most　test　data.　©　2016,　Chinese　Institute　of　Electronics.　All　right　reserved.