Narrative texts often contain several characters, and these characters have different levels of importance in the text. For example, some characters play primary protagonists, whereas others play supporting or minor roles. These characters are introduced in different orders and presented through different types of character expressions, such as proper nouns, pronouns, or role descriptions. When an author uses pronouns to refer to the characters mentioned in earlier sentences, readers must figure out which characters the pronouns are referring to. Therefore, pronouns can be integrated in earlier sentences. As a result, in later sentences, referential processing becomes essential for building discourse coherence. The order of mention and the types of character expression affect readers’ pronoun resolution; and developmental data in the literature have shown that the ages of readers affect their pronoun resolution, too. The present study focused on how three factors affected pronoun resolution, namely the order of mention, the type of character expression, and the reader’s age. We recruited 24 college students and 26 sixth grade students as the study participants. A three-way mixed design (age × order of mention × type of character expression) was adopted to examine the interaction patterns of these factors. The participants were asked to read texts sentence-by-sentence at their normal speed, and the reading time was then recorded. The results showed that no three-way interaction occurred. Two-way interactions were further examined in participants from separate age groups. The adult participants were unaffected by the order of mention and type of character expression. The sixth grade students were unaffected by the type of character expression when a pronoun referred to the first-mentioned character; however, in terms of the second-mentioned character, the proper name expression of the characters enhanced pronoun resolution in readers. This implies that the name of the character is more important than the role description for readers. Moreover, the reading time patterns were observed to be similar across these four two-way conditions for both age groups. Finally, some applications of pronoun resolution instruction and practical examplaes are serve as suggestions for teachers.