Abstract: From the perspective of institutionalism， national reform is concerned with reforming the formal institutions and changing the informal ones. However， the redesigning of the formal institutions， subjected to the subjective factors of decision makers， will inevitably produce a variety of discordance and even conflict with the informal institutional system. During the Argentine national reform in 1980s and 1990s， the policies of economic liberalization clashed with the informal rules of traditional populism， and the policies of political democratization kept reinforcing the traditional informal rules of “local clientelism”. Such an interaction between the formal system and the informal system greatly affected the stability of the countrys political and economic system， and eventually led to a national crisis.

Key words: reform, formal institution, informal institution, populism, local clientelism