In Chinese Buddhism, Kwan Yin (Guanyin or Kuan Yin) is synonymous with the Bodhisattva Avalokitesvara, who is a pinnacle of mercy, compassion, kindness and love. A Bodhisattva is a being of enlightenment or “bodhi,” one who has earned the state to leave the world of suffering and destined to become a Buddha. Rather than enter the bliss of nirvana, they vow to remain in order to save humanity.

Kwan Yin's veneration was introduced into China around the 1st century CE. The Bodhisattva is represented prior to the Song Dynasty (960-1279) as masculine. Images later appear either male or female, as a Bodhisattva could appear in which ever form is needed to relieve suffering. The association with the seventh century Buddhist saint Miao Shan in the 12th century furthered the appearance as female. By the modern period, Guan Yin is usually shown as a white-robed woman.

See: Anh Q. Tran, SJ, Kuan-Yin: A Case of Inculturation in Chinese Buddhism, for a more detailed explanation, https://bit.ly/2MOpWko