For proper assessment, diagnosis, and treatment of language disorders in Mandarin children, it is important to have measures that closely track the course of normal development. The current study uses a large collection of spontaneous conversational language samples to track the developmental course of five language measures: mean length of utterance (MLU), the MLU of the five longest utterances (MLU5), vocD, number of repetitions, and number of retracings. We used cross-validation-based linear regression to estimate the relationship between age, gender and each of the five variables derived from the conversational language samples in 101 typically developing Mandarin-speaking children aged 3 to 7. Each of the five measures showed significant age-related effects during the period from age 3 to age 7. As norm-referenced measures of language development in children speaking Mandarin, these developmental data could inform clinical therapists regarding assessments and interventions for children with language disorder or impairment.