The article characterise the reform of the National Statistical Systems (NSS) carry out by the African Portuguese Speaking Countries (APSC) on the sequence of the political, economic and social transformations that takes place at the 2nd half of the eighties, with constitutional revisions adopting the models of multiparty democracy and market economy, originating the need of news NSS replacing the Systems built after its independences to respond to the models of political and economic organisation adopted at the time, completely different from those of the present.
Besides the characterisation of the NSS of the APSC, an analysis of comparative law is made taking as conceptual reference the Principles of Official Statistics approved by the Statistical Commission of the United Nations in April 1994.
keywords: national statistical system; structural and structurally elements; bodies; principles.