Purpose: Sentence repetition (SR) is believed to be a clinical marker for developmental language disorder (DLD) across many languages. This study explored the potential of a self-designed Mandarin SR task (MSRT) to reflect Mandarin-speaking preschoolers' language ability and to differentiate children with and without DLD in this population. Furthermore, we aimed to compare five scoring systems for evaluating children's MSRT performance. Method: In Study 1, the MSRT was administered to 59 typically developing (TD) children aged 3;6 (years;months) to 6;5 in China. The task was examined regarding its ability to correlate with language indices derived from children's narrative samples. In Study 2, both a TD and a DLD group were recruited to investigate the task's sensitivity, specificity, and likelihood ratios to distinguish between children with and without DLD. Results: Study 1 showed that, using four of the five scoring methods, TD children's performance on the MSRT significantly correlated with all the language measures derived from narratives. Study 2 showed that the MSRT was able to differentiate children with and without DLD. Conclusion: The MSRT is a promising tool to reflect language abilities and identify DLD in Mandarin-speaking preschoolers. Based on the current evidence, we recommend that researchers and clinicians select the number of errors in the syllable method or the binary method when scoring responses to meet their specific needs.