The Mexico Political Reform of 1977 was initiated to revitalize the electoral process and re-legitimize the government party and national political institutions. During the previous decade, Mexican politics had become increasingly violent as opposition increased and groups moved outside the political arena to affect change on the system. The 1977 Reform was designed to increase incentives for critics to work within the political system by changing procedures for political party recognition, enlarging the national legislature, and establishing a two-tiered electoral system with partial proportional representation. By all reports the reforms enacted were successful in changing the electoral process. But little is known about the impact of the reforms on the operation of the national Chamber of Deputies which has absorbed the new opposition political parties. This research examines how the reforms of 1977 has influenced the path of Mexican democratic government. Based on a pre and post-reform research design, legislative rules and well as legislative business (in the form of bill introduction, amendment and passage) will be collected for the period 1970-1993. The results of this research will demonstrate the utility of the "new institutionalism" perspective for explaining legislatures outside the United States and Europe. * * *