Exhibition introduction: Four watercolor portraits of Xu Guangqi, Nan Huairen, Matteo Ricci and Tang Ruowang were painted at the Shanghai Tushanwan Painting Gallery in the early 20th century. Participated in the Panama Pacific International Exposition held in the United States in 1915. The inscription on the painting is written by Ma Xiangbo and written by Xia Ding in Yi script. The original painting is now collected in the "Matteo Ricci Institute of Chinese and Western Culture and History" at the University of San Francisco.