This study examined how classifier-noun conventions and classifier semantic compatibility influence the selection of classifiers in Mandarin- speaking children aged five to seven. Results indicated that children’s classifier use was shaped not only by conventional associations between classifiers and noun categories but also by semantic congruence, particularly in the absence of explicit noun labels. Older children demonstrated greater sensitivity to labels in guiding classifier selection than younger children. Furthermore, explicit noun labels most strongly boosted children’s choice of conventional classifiers for non‑prototypical stimuli, while having a much smaller impact on prototypical stimuli. Overall, these results highlight the interplay between memorization and semantic compatibility in classifier acquisition and underscore the importance of semantic and perceptual features in shaping language learning.