Cheng Oi Ki started learning the ocarina in 2004, and two years later she passed the China Artist Association Grade 9 Ocarina Professional Certificate Exam. She was also awarded the Grade 3 certificate in the clarinet from Associated Board of the Royal Schools of Music in 2006. In the same year, she won a gold prize representing Hong Kong at “The United Nations Second World Chinese Art Magnificent Ceremony”, which was held in Beijing.
Oi Ki has also taken an interest in visual arts, including paper art and pottery. In 2010 her artworks were exhibited at several art events, including her anaglyph art which was put on display to the public at the 2010 Hong Kong Flower Show.