Research on the Old Chinese phonology is the process of truth-seeking, in which the rigorousness of methodology is a very important link. In recent years, considerable achievements have been made in Sino-Tibetan comparison. However, there are no acknowledged criteria of the selection of cognates. The present dissertation supposes that xiesheng (諧聲) characters and family words (同族詞), as basic material for Old Chinese phonology, should not only be attached just importance to but also be brought into full play in methodology, although a breakthrough has been made in Sino-Tibetan comparison. Therefore, this article adopts ”word family” to observe the initial consonants in Old Chinese, and then takes ”xiesheng series” as collateral evidence to propose new thinking on the reconstruction of the initial consonants in Old Chinese.