Due to the investigation into the syncretism of 49 prepositions in Chinese 38 dialects, we’ve found that the syncretism of Source, Location and Goal in Chinese can be explained through two kinds of syncretic models. One is bi-directional syncretic model. In this model, Location and Source can be syncretized bi-directionally and Location and Goal also can be syncretized bi-directionally so that it will appear a case in which one word can express Source, Location and Goal. But in this model, the syncretism of Source and Goal needs to be explained exceptionally. The other is unidirectional circular syncretic model. In this model, Goal derives from Location, and Source derives from Goal, and Location derives from Source, which forms a circulation. We think that the complicated relationships between Source, Location and Goal in Chinese dialects are the corollary of interaction of multiple factors.