This study investigated whether listening comprehension played a mediator role between vocabulary and reading comprehension. 127 Mandarin-speaking children were longitudinally assessed at 6;4, 6;10, 7;4, and 7;10. Data were collected in four batteries of tests implemented at the beginning of first grade (T[subscript 1]); at mid-first grade (T[subscript 2]); at the beginning of the second grade (T[subscript 3]); and at mid-second grade (T[subscript 4]). Participants' IQ, decoding, vocabulary breadth and depth knowledge were measured at T[subscript 1], listening comprehension at T[subscript 2], and reading comprehension at T[subscript 3] and T[subscript 4] respectively. Path analysis was utilized for analysis. Vocabulary breadth was found to contribute to reading comprehension via a full mediator role of listening comprehension with a lapse of 1 and 1.5 years; however, vocabulary depth directly influenced reading comprehension with the same time lapse over the effect of decoding and listening comprehension.