There are four types of characters , , , , in oracle bone inscriptions, which are similar and their usage is crossed. Previous scholars did not identify the above four characters as the same character. Through the analysis of philology, the above four characters are identified as monosyllabic variants. In this paper, we believe that these four characters are a word pronounced “si”, indicating that both hands hold a pestle to poke meaning. However, the specific corresponding text of these four characters has not been found. In addition, the so-called phenomenon of “two persons co-divination” is also discussed, and it is considered that whether there is a phenomenon of “two persons co-divination” in oracle bones inscriptions lacks definite evidence and needs to be discussed.