With vast empirical material analyzed, the authors investigate the place and role of political parties in the legislative assemblies of the Russian Federation's regions. The article contains description of those factors (the institutional one, the one related to electoral law, the geographical one) which proved conducive to the weakening of parties' influence in the legislatures in late 1990s to early 2000s. Indicators are offered for the estimation of the legislative assemblies' party inclinations, with, for that matter, differentiated account taken of the declared party membership of a candidate and of the real party adherence of a mandate holder. The main electoral systems that have been in use in the RF subjects during the past decade, are characterized; cases of parties' success at elections cited. Statistical data of deputies' party adherence are presented, the problem of factions and deputy groups analyzed. The regions are classified according to the party make-ups of their assemblies. A general conclusion is made, to the effect that change of the Russian parties' substantiality component is a matter of historical perspective.