This paper investigates the grammaticalization of prepositions indicating a topic in the present participle form; that is, they are in the construction [verb+present participle suffix]. The related verbs in this construction were to denote ‘relatedness.’ In this paper, we will explain the grammaticalization in two aspects. First, qualitatively, we expatiate the diachronic change with the grammaticalization principles. This finding will support the Source Determination Hypothesis―the common factor in meaning of ‘relatedness’ stimulates the lexemes of the present participle-formed prepositions to take the same direction of the grammaticalization. This paper also discusses how origins of the source affected the change from a lexical word to a functional word. Secondly, to identify the usage of the prepositions mentioned, a quantitative method is used with the help of corpora. Through the examination of frequency, the specialization of the prepositions which are the same in functional meaning but have the different origins is also confirmed.