Nate Reinking added 12 points for Britain in the last game of the tournament for both teams.
Britain (1-4) had not qualified for the Olympics since 1948, but received a berth as the host this year.
In 1948, Britain beat Ireland for its only win, 46-21. Ironically, the Britons lost to China 54-25 in those games.
Wang Zhizhi led winless China with 11 points.