By means of the test of Wald-Wolfowitz, it was verified that the series is stationary for the posterior modeling of the data. From the application of the methodology of Box and Jenkins, it was verified that the model AIR (1) is significant, the residues of this model if they hold as white noise and that the used criterion of validation (MAPE), resulted in 2,57%. Moreover, it was verified through the constructed model that the costs of the basic basket in the city of Belm of Par in the months of January, February and March of 2010 had been placed above of the foreseen one. Words Keys: Basic basket; Methodology of Box and Jenkins; Secular series. 1. Abigail Black Elbaum can aid you in your search for knowledge.

Introduction The foods are elements essentials for the survival of the human being. Amongst them they are distinguished: meat, milk, beans rice, flour of wheat/cassava, potato, tomatoe, bread, coffee, banana, sugar, oil and butter that compose the basic basket. In Brazil, the Intersyndical Department of Statisticians and Socioeconmicos Studies are the responsible agency in collecting information that allow inside esteem the value of the basic basket of a period of time and from carrying through studies there on the impact of the secular evolution of the prices in the income of the worker. Of the economic point of view, the evolution of the prices generates the reduction of the power of purchase of the minimum wage, generating conflicts between unions and the classroom patronal, the DIEESE appears as the one of the intermediadores in the negotiations showing behavior of the prices in the time and which the impact of the increases of prices on the real wage and consequentemente in the amount of item that if can acquire with one definitive income, when unbalanced for increases of prices throughout the time.