This study investigates qualitatively and quantitatively 3‐year‐old Mandarin‐speaking children’s error patterns in two nonword repetition tasks which differ in their degrees of wordlikeness, i.e., the nonce word and the gap word sets. Their performances in the two tasks were transcribed and analyzed from two respects: (1) the rate of a specific unit retaining the target structure and (2) the cross comparison between linguistic units and error processes. Results showed that tones and syllable structures of the target forms were easier to retain than the contents. And even though children’s error patterns approximated the adults patterns in gap word repetition task, they had strategic difference in dealing the weight decay in memory: while the children used syllable and rhyme substitutions, the adults used syllable omissions. Our study has implied that children have the same processing mechanism with adults in learning novel words. However, their strategic difference may have an implication for language learning. In addition, the present study also contributes the processing of tone to the linguistically constrained model (Hartley & Houghton, ‘‘A linguistically constrained model of short‐term memory for nonwords,’’ J. Mem. Lang. 35, 1–31 1996), so that it can become a more complete model in demonstrating how novel sound sequences are learned and recalled in Mandarin‐speaking young children. Copyright © 2006 AIP Publishing LLC.