This study investigated 4-year-old children's knowledge of the structural constraints on ellipsis constructions in Mandarin Chinese, focusing on the structural difference between verb phrase (VP) ellipsis and null object constructions. In Mandarin Chinese, if the antecedent clause of a VP-ellipsis structure contains an adverbial modifier, this adverbial modifier must be recovered at the elided site in the second clause. However, if the antecedent clause of a null object construction contains an adverbial modifier, the reconstruction of this adverbial modifier at the elided site is not necessary. Two experiments were conducted to examine whether young Mandarin-speaking children are sensitive to this structural difference between the two ellipsis constructions. The results show that children exhibited adult-like performance in both experiments. This is evidence that young Mandarin-speaking children have knowledge of the structural difference between VP-ellipsis and null object constructions with regard to adverbial recovery. We interpreted the findings in conjunction with previous research as evidence that children's knowledge of the structural constraints on ellipsis constructions is innately specified.