Gai Qi 改琦 was a Chinese painter and poet active during the three Qing dynastyreigns of Qianlong (1736-1796), Jiaqing (1796-1821), and Daoguang (1821-1851). His name can be often seen in publications that are associated with the history of Qing painting, the genre of shi-nü-hua 仕女畫 or illustrations related to Chinese classic novels. However, past works on painting history only offer a brief introduction to Gai Qi and barely mention his other works. Besides being well-known for Illustration of Dream of the Red Chamber 紅樓夢圖詠, very little is studied about this artist. There are various publications that mention Gai Qi and his works, however, questions have been asked but never carefully addressed, such as the function of specific paintings, his painting techniques, and the connection between his religious background and artworks. This thesis explores these issues by examining three of Gai Qi’s extant paintings in American collections, Portrait of Lüzhu (綠珠小像圖), Famous Women (列 女圖冊) and Four Luminaries of Mount Shang (商山四皓圖). The study fills in gaps in the understanding of Gai Qi as a Muslim painter in the Qing dynasty and on his works in shi-nü-hua and other genres. In addition, this work begins to reveal the contribution of Gai Qi’s paintings to the history of Chinese painting during the 18th to 19th century, the period of transition between 18th-century styles, and the rise of Shanghai painting styles in the mid to late 19th century