The purpose of this study is to analyze the impact of the growth of Brazilian winter corn crop on spot price seasonality, basis patterns, and the integration to international market. A moving average method and regression analysis were used to test for seasonal variations, while econometric time-series methods tests were applied to verify the market integration. Results indicated that the expansion of the winter corn crop has changed the seasonality of prices and basis and increased the level of integration with the international market. crop on spot price seasonality, basis patterns, and the integration to international market. A moving average method and regression analysis were used to test for seasonal variations, while econometric time-series methods tests were applied to verify the market integration. Results indicated that the expansion of the winter corn crop has changed the seasonality of prices and basis and increased the level of integration with the international market.