China’s booming economy has increasingly allowed more of its young men and women to seek a college education in the West; 329,000 now study in the United States, more than five times the number recorded a decade ago. By far the largest contingent of foreign students, they can be an economic lifeline for colleges, since they usually pay full tuition, and they can provide a healthy dose of international diversity.

But those students often bring to campus something else from home: the watchful eyes and occasionally heavy hand of the Chinese government, manifested through its ties to many of the 150-odd chapters of the Chinese Students and Scholars Associations.

The groups have worked in tandem with Beijing to promote a pro-Chinese agenda and tamp down anti-Chinese speech on Western campuses. At Columbia a decade ago, the club mobilized students to protest a presentation about human rights violations in China, urging them to “resolutely defend the honor and dignity of the Motherland.” At Duke, the group was accused of inciting a harassment campaign in 2008 against a Chinese student who tried to mediate between sides in a Tibet protest. More recently in Durham, England, the group acted at the behest of the Chinese government to censor comments at a forum on China-Hong Kong relations.

In rare instances, members of the student group have been accused of spying.

The organization’s influence troubles some China scholars and human rights activists, who say it wields outsize sway over American campuses because of the sizable tuition paid by Chinese students abroad, a group recently exhorted by China’s government to increase their patriotism and devotion to the Communist Party.

“I basically don’t think that any student organizations that are controlled by their government — which clearly the C.S.S.A. is — should have a presence on foreign university campuses,” said Jeffrey Henderson, a professor of international development at the University of Bristol in England.