Initially created as a saving asset that should guarantee future income to their participants, the Pension Funds took an important role in the Brazilian economic scenario. The legal necessity of distribution of more than 450 billion reais (Brazilian Money) into assets of fixed income, of variable income, of real estate and loans & financing assets, created investment’s portfolios that in a diversified way financed profitable activities in Brazil. Nevertheless of having a strong synergy in the main objective and also in their macroeconomic scenario, Public Pension Funds and Private Pension Funds have not only considerable differences of investment’s portfolio, but they are also responding the variation of a few macro-economic variables in a different way. Therefore, analyzing the 10 biggest investments in the Public & Private`s Pension Funds between the years of 2002 and 2008, this work aims to discuss the sensibility of the investment`s portfolios of the Pension Funds during macro-economic changes. In the studied period, was observed that between 2002 and 2007 a percentage raise in the investments in the stock market in both Public and Private Pension Funds. In the year of 2008 these kinds of investments decreased in also both Pension Funds. Despite of that, it is observed that the Private Funds have been more conservative, keeping almost 70% of their total amount in fixed income assets. The only asset of fixed income where was verified a higher percentage level in the Public Funds was in the Letras Financeiras do Tesouro (Treasure Bonds). The statistic methodology used was the dynamic regression, in which the dependent variables were the investments in the different assets of the Pension Fund`s portfolios and the dependent variables were the ones that represented changes in the macroeconomic scenario (e.g.: Gross Domestic Product, dollar e interest rate ). The results indicates a correlation between some macro-economic variations and the composition of the investment`s portfolios in the Pension Funds. But, the it also indicates that a few of these macro-economic variations influence in a different way the Public and the Private Pension Funds.