The Altaist conducted a lot of researches on Altaic languages. To investigate the relationship between the Altaic languages they have established many phonological and morphological correlations. As a result of these researches, both positive and negative views on the relationship of the Altaic languages has been determined. Although there are many studies on the morphology of the Altaic languages studies on passivity suffix is limited. These studies on passivity suffix are conducted by Ramstedt, Poppe, Benzing, Gronbech, Clauson, Talat Tekin, Choi.
The paper includes studies on the passivity suffix of the Altaic languages and depending on these studies, the situation of passivity suffix of the Altaic languages is analyzed. Furthermore, the development of passivity suffix in the old and today Turkish languages is tried to be proved with the help of some examples. As a result of the research, passivity suffix is proved mostly as voice suffix in old and today Turkish language. In Mongolian, Manchu-Tungusic and Japanese passive sentences are made with different suffixes but in Korean language voice of “I” can make a passive meaning to the sentence.
Key words: Altaic Languages, Old and Today Turkish Languages, Passivity Suffix, Morphology.