近年，接尾辞性字音形態素（用法上，字音接尾辞に準ずる，または近似する字音形態素）に関する研究は多く見られる。しかし，接尾辞性字音形態素にどんな語彙が前接でき，どんな語彙が前接できないのか。これについては未だに明らかになっていない。そこで本稿では，接尾辞性字音形態素の前接部を語種・品詞で分類し，考察した。結論として，接尾辞性字音形態素は和語を前接する場合，その和語は名詞・サ変動詞でなければならない，という制限があることが分かった。接辞性字音形態素は漢語との親和性をもち，漢語に最も付きやすい。その波及効果により，漢語と同じような品詞をもつ和語にも付くようになったのだと考えられる。

Recently, there are many papers focusing on Sino-Japanese suffix. However, what has not been proved is if there is any lexical limitation on the preceding part of Sino-Japanese suffix. In this research, we did an analysis through the preceding parts data of 9 Sino-Japanese suffixes. We found that the preceding part of Sino-Japanese suffix should mainly be a Sino-Japanese word. Besides, a foreign word is also allowed. On the contrary, we cannot use a Japanese native word to Sino-Japanese suffixes, unless it is of equal lexical category to Sino-Japanese word. In fact, when the preceding part of Sino-Japanese suffix is a Japanese native word, it has to be a noun or a suru-verb, but not an adjective or a gerund. From these rules, we can infer that the prototype of Sino-Japanese suffix is to use to a Sino-Japanese word. And it also spreads to cases using to other types of words if their natures are similar to Sino-Japanese words.