蒙古语已经有近千年的文字史,在这近千年的时间里由于文字和语言的发展变化不平衡,书面语和口语领属格词缀之间产生了一定差别。通过分析和解释这些差别产生的原因,了解了领属格词缀的更早期形式。根据蒙古语族诸语言领属格词缀并结合阿尔泰语系其他语族语言领属格词缀,得以重建了共同蒙古语时期领属格词缀为*-1n、*-in。 Mongolian language has a history of nearly a thousand years of writing. During the past millennia, due to the imbalanced development of words and languages, there has been a certain difference between written and spoken affiliation. By analyzing and explaining the causes of these differences, we understand the earlier forms of genitive affixes. According to the affiliation of Mongolian linguistic genres and the affiliation of genres in other languages ​​of Altaic languages, the affiliation of affiliation with Mongolian Mongolian language was reconstructed as * -1n, * - in.