Screenwriter Scott Darling reuses his Mr. Wong in Chinatown (1939) script from eight years earlier for Roland Winters' debut as Chan.
Victor Sen Yung had previously played "Jimmy" Chan in the series, but in this episode in the series the character's name inexplicably becomes "Tommy" Chan.
The 42nd of 47 Charlie Chan movies.
"The Chinese Ring" was filmed in 1947 and released on December 6. Sydney Toler's death on February 12, 1947 lead to this being the debut of Roland Winters as Charlie Chan.
It seems very likely that a Chinese princess who is fluent in English (as the one in this film is shown to be when she arrives at the house in the opening scenes) would write her dying words in English, as she's clearly aware that those who might help solve her murder, including police, reporters, and even Charlie Chan and his son, would collectively be able to read her writing better than if it were penned in Chinese.