Order α_s² perturbative QCD corrections to the Gottfried sum rule

The order $\alpha_s^2$ perturbative QCD correction to the Gottfried sum rule is obtained. The result is based on numerical calculation of the order $\alpha_s^2$ contribution to the coefficient function and on the new estimate of the three-loop anomalous dimension term. The correction found is negative and rather small. Therefore it does not affect the necessity to introduce flavour-asymmetry between $\bar{u}$ and $\bar{d}$ antiquarks for the description of NMC result for the Gottfried sum rule.