本研究旨在探討漢語母子對話中兒童「然後」的使用與其功能。研究語料來自於八位年齡介於兩歲七個月到五歲四個月的兒童，並分成兩組：年紀較小之兒童(平均兩歲十一個月)與年紀較大之兒童(平均四歲十個月)。本研究主要根據Su (1998)的分類，把兒童「然後」分為連接詞(connective)及言談標記(discourse marker)的使用。連接詞的使用有時間性(temporal)、遞增性(additive)、因果性(causal)及轉折性(contrast)四項功能。言談標記的使用有填補語(verbal filler)、主題接續(topic succession)及主題再開(resumptive opener)三項功能。研究結果顯示年紀較大之組的兒童使用「然後」的次數較多。隨著兒童年齡增長，言談標記使用的增加比連接詞的增加還多。「然後」當連接詞時，時間性功能使用得最多。與Yeh (2011)「然後」在敘述文中的研究比較，其顯示出「然後」在敘述文中出現得比在對話中還多。另外，時間性功能隨著年紀減少，而遞增性及因果性隨著年齡增加，可用Winskel (2003)的「概念複雜性」(conceptual complexity)來解釋。「然後」當言談標記時，兒童填補語使用得最多，其隨著年紀增加而減少使用。主題再開兩組都使用得少，而主題接續只出現在年紀較大之組別。總結，兒童在「然後」的使用上有發展上的不同。 / The study investigated Mandarin-speaking children’s different use of ranhou at different ages in mother-child conversations. Eight subjects aged from 2;7 to 5;4 were divided into two groups; a younger group (mean age: 2;11) and an older group (mean age: 4;10). In this study, the children’s use of ranhou was categorized into connective use and discourse marker use, mainly based on Su’s (1998) classification. The connective use of ranhou includes temporal, additive, causal, and contrast functions. The discourse marker use of ranhou contains verbal filler, topic succession, and resumptive opener functions. The results showed that older children used more tokens of ranhou than younger children. As children got older, the discourse marker use of ranhou increased much more than the connective use of ranhou. In the connective use of ranhou, temporal ranhou was the most frequent function. Compared with Yeh’s (2011) study of ranhou in narratives, it may be suggested that ranhou occurs more in narratives and less in conversations. Additionally, the temporal function decreased with age whereas the additive and causal functions increased with age, which could be explained by Winskel’s (2003) conceptual complexity. In the discourse marker use of ranhou, the verbal filler function was used the most and decreased with age. The tokens of the resumptive opener function were few in both groups, and the topic succession function only occurred in the older group. To conclude, the results suggest that there is a developmental difference in children’s use of ranhou.