An important debate exists on whether soybean expansion in Brazil is responsible for putting more pressure on the Amazon forest or if it allows land use intensification through the recuperation of degraded pasture. In this paper, we estimate regional soybean supply own and cross price elasticity in order to better assess the possible impacts of agricultural trade liberalization in old and new soybean production basins. Applying a panel data estimation technique, we find large substitution supply elasticity between soybean and beef in Brazil Moreover, own price elasticity of soybean supply is much higher in Cerrados regions that in the South of the country. These results allow to discuss possible regional consequences of soybean trade liberalization on the Amazon forest. The current movements to promote sustainable and responsible soybean production in Brazil could certainly modify the future response of the sector to trade liberalization and its long term impacts.