The Robert B. Jay Collection documents some of the research Jay conducted on various topics related to WWII-era China, including the Hempel Family who ran a butchery and restaurant in Peking [present day Beijing]. The Hempel's shop was frequented by U.S. Marines who called themselves "Knights of the Round Table," named so for the round table they would gather around in the back of the shop. Other research topics include Catholicism and Catholic landmarks in China; Chinese traditions; U.S. Marine service in China; Chinese cities such as Tientsin [present day Tianjin], Peking/Peiping [Beijing], and Shanghai; the Boxer Rebellion; and Israel Epstein, an Old China Hand. The materials include reproductions of maps, research articles, correspondence, and photographic prints. Of particular note are Rashed's Pictures, possibility depicting the Tientsin flood of 1939, with captions on the back written in Uighur and English.

Also included in the collection are two video recordings of a China Marine Reunion Tour of Mainland China recorded in 1990 and a bamboo or wooden Chinese Yo-Yo, known as a diabolo in other cultures.

The collection is arranged alphabetically by subject.