Unlike studies using party identification to examine citizens’attitudes toward political parties, this essay introduces the concepts of party necessity and party trust to explore citizens’ attitudes toward a political party. Three assumptions are provided and tested based on the existing literature and Taiwan’s experiences. First, in a democracy, the majority of citizens confirm that a party is a necessity while maintaining a widespread distrust toward parties. Second, the citizens’ evaluations of party functions will have effects on party necessity. Third, the citizens’ evaluations of party functions and satisfaction with party performance will also generate effects on party trust.The findings confirm these hypotheses and several implications are of special importance. In the discussions on party change in western democracies, the phenomenon of party function decline has been regarded as a potential contention of a party’s pivotal status. Yet, from the perspective of a functioning democracy, a political party does play anindispensable role in the operation of a democracy. As in most democratic counterparts, citizens in Taiwan maintain an ambivalent attitude towards political parties. While citizens acknowledge the necessity of political parties for the operation of a democracy, they also maintain a rather high degree of party distrust. In terms of party necessity, this essay finds that citizens’ evaluations of party functions will affect their attitudes toward the necessity of having parties. Citizens are more likely to accept the necessity for parties as they uphold more positive evaluations of party functions. In addition, this essay also finds that citizens’ evaluations of party functions and party performance will affect the citizens’ trust in the party. It is argued that the citizens’ evaluations of party functions and party performance are closely associated with the citizens’ assessments of politicians’ respective performances. The functioning of a political party depends on the behavior of individual politicians who belong to the party. To some degree, therefore,the assessment of the politicians’ performance will become one of thesources of the citizens’ trust in the party.