This paper focuses on the determinants of inflation under different policy rules and fixed exchange rate regime. The purpose of this paper is to check the behaviour of inflation in fixed exchange rate regime for a flexible targeting period and a period of strict targeting. The data used are mainly from the World Bank, in «the book of world development indicators» contained in the CD -ROM (WDI 2013). Working for the periods 1977-1994, 1995-2012 and 1977-2012, the analysis was done with a dynamic panel that has the distinction of being among the independent variables, the endogenous variable lagged one or more periods. The endogenous variable is the rate of inflation. Estimates made from the Arellano and Bond (1991) method, it is clear that during the period of flexible inflation targeting, money supply, trade balance and the exchange rate are the main determinants of inflation. During the period of strategy of strict inflation targeting, the main determinants of inflation are the benefits of natural resources, the trade balance and the economic crisis.