His subject matter included landscapes, animals, feathers, and other elements, and his art used rich, varied forms alongside strong and vivid colors.
[2]: 52 In the same year, President Chiang Kai-shek and his wife Soong Mei-ling selected eight of Au's pieces for the collection in the Zhongshan Building in Taipei,[2]: 57 where they have remained on display for decades.
[2]: 59 Beginning several years after settling in Taiwan, Au helped spread Chinese culture worldwide through his participation in international exhibitions.
[2]: 138–139 Au's work is characterized by the Lingnan School's use of colors, white space, and skeletal structure, along with a combination of modern and Western elements.
In his later years, he integrated poetry and calligraphy into his paintings, earning him a reputation as an artist embodying the humanistic spirit of Eastern cultural tradition.