We analyzed epidemiologic characteristics and distribution of 1,067 human plague cases and 5,958
Yersinia pestis
isolates collected from humans, host animals, and insect vectors during 1950–2019 in 4
Marmota
plague foci in China. The case-fatality rate for plague in humans was 68.88%; the overall trend slowly decreased over time but fluctuated greatly. Most human cases (98.31%) and isolates (82.06%) identified from any source were from the
Marmota himalayana
plague focus. The tendency among human cases could be divided into 3 stages: 1950–1969, 1970–2003, and 2004–2019. The
Marmota sibirica
plague focus has not had identified human cases nor isolates since 1926. However, in the other 3 foci,
Y. pestis
continues to circulate among animal hosts; ecologic factors might affect local
Y. pestis
activity.
Marmota
plague foci are active in China, and the epidemic boundary is constantly expanding, posing a potential threat to domestic and global public health.