The article deals with three cases of the influence of the devaluation of the rouble on vectors and dynamics of the Russian foreign trade. It shows that only in one case of the three commodity flows reacted on the sharp depreciation of the rouble in a manner stated by the theory: vectors of exports and imports were opposite - the first grew and the second decreased. In the year following the devaluation each vector changed adequately as the theory predicted in two cases of the three. It is noted that the weakening of the national currency leads to the increase in rouble equivalents of the currency earnings and the costs of importers for the purchase of foreign goods that is bound to stimulate exports of domestic products and discourage the imports of foreign goods. It is concluded that the dynamics and vectors of the foreign trade depend to a significant extent on the changes in the exchange rate. At the same time the foreign trade is also sensitive to other internal and external factors, particularly world prices.