The present article has as objective to calculate and to analyze the level of the synergic interactions and the overflow of the multiplying effect of the sectorial production between Parana and the Rest of Brazil (Brazil except Parana), using interregional systems of input-output estimated for the years of 1995 and 2000. The main results showed that : a) the dependence of the production of Parana in relation to the flow of trade with the Rest of Brazil raised from 25% in 1995 to 33% in 2000; b) only 1.36% of the production of the Rest of Brazil depended on the flow of input (goods and services) between this and Parana in 1995, reducing this dependence to 0,56% in 2000; c) the overflowing average of the multiplier effect of the production of the sectors of the economy of Parana in direction of the Rest of Brazil raised from 16% in 1995 to 20% in 2000, while in direction of the Rest of Brazil-Parana, it kept on 1%.