  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.
