今日多以「祖父母」稱呼自己的尊二輩直系血親，但作為親稱，「祖父母」並未見於目前所見的商周甲骨文、青銅銘文及出土的秦漢簡牘，反而從戰國時期開始，簡牘中已可確定使用「大父母」來指稱尊二輩直系血親，「祖父母」實屬晚起之用法。「大父」、「大母」已出現於商代，但二者都屬於帶有「大」字親稱的成員之一，指稱的對象並非今日的祖父母，而是同輩親屬中具有特殊身分之人，「大」作為橫向親屬中的區別字使用，含有「最大」意。「大父母」從戰國時期開始指稱祖父母，此時《儀禮》與《禮記》中的〈喪服〉篇章也出現「祖父母」之詞，但除〈喪服〉篇章外，文獻與出土簡牘幾乎皆用「大父母」，約至兩漢之交才混用「祖父母」，且秦漢的法條持續使用，直到西晉泰始律才改用「祖父母」，其改用應與「準五服以制罪」的原則有關。然而，「大父母」並未消失，近代文獻仍然見到，只是從戰國時期以後，因「大父母」已轉變為指稱祖父母，所以商代原本用來指稱「同輩」親屬中之最大者意，已不復見到。

Today, people often refer to their second-generation direct blood relatives as “grandparent”, however, as a relative title, “grandparent” are not found in the oracle bones and bronze inscriptions of the Shang and Zhou dynasties and the unearthed bamboo slips of the Qin and Han dynasties, on the contrary, since the Warring States period, bamboo slips have been able to use “oldest parents” to refer to the direct blood relatives of the second generation, so “grandparents” is a relatively late usage. “Oldest father” and “Oldest mothe”\" have already appeared in the Shang Dynasty, but they are both members of the family with the character “oldes” in their names, and they do not refer to today’s grandparents, they are people with special status among relatives of the same generation. “oldest” is used as a distinguishing word in horizontal relatives, which means “oldes”. “Oldest parent” began to refer to grandparents from the Warring States period, at this time, the words “grandparents” also appeared in the “Mournin” chapters in “Yi Li” and “LI J”, however, except for the chapter “Mourning”, almost all documents and unearthed bamboo slips use “oldest parents”, and it was between the Western Han and the Eastern Han Dynasty that “grandparents” were mixed. moreover, the legal provisions of the Qin and Han Dynasties continued to use “eldest parents”, and it was not until the Tais-hi Code of the Western Jin Dynasty that the word “grandparents” was changed. The reason for its change should be related to the principle of “establish penalties according to the funeral system”. However, “eldest parents” have not disappeared, and can still be seen in modern documents. However, since the Warring States Period, because “eldest parents” have changed to refer to grandparents, it was originally used in the Shang Dynasty to refer to the eldest relatives of the same generation, is no longer seen.