Shizen-ei is a concept for classifying different subjects of tanka, considered to be the category in contraposition to what has been referred to as Shakai-ei (poems about society) which describes various matters, including the society in which people live and the perception toward the society.
短歌の対象を分類する概念で、人の生活する場である社会と社会に対する認識等を詠んだいわゆる社会詠と対照される分野であるとされる。