According to the Institute for International Education's "Open Doors" report, one-third of international undergraduates in the United States come from China, India, and South Korea. China had the most—40,115 in the 2009-10 academic year. That number is expected to grow as more Chinese families become able to afford to send their children to study abroad.
There were more Chinese undergraduates on American campuses in 2009-10 than undergraduate, graduate, and nondegree students from all of South America (32,564) or Africa (37,062). Brazil—the top South American nation sending undergraduates to the United States—had 4,083 students in the country during that time period, and Nigeria, the top African source, had 3,498.
While the Asian pipeline is valuable, international-admissions officers don't want to become too reliant on it.
"While we welcome these very bright, qualified, eager students, we are concerned about the risk that's involved with having a lot of students from one country," says Marjorie S. Smith, the University of Denver's associate dean of international admission. More than half of Denver's overseas applicants are from China.
Ms. Smith says the university doesn't want to repeat problems that arose during the Asian economic crisis of 1997, when the flow of students from Indonesia, Malaysia, and Thailand dried up.
"Those countries have never fully recovered in terms of regaining the levels of student mobility," she says. "From that we learned in order to reduce risk, you really have to keep your international population diverse."
This year Denver set aside $100,000 to provide financial aid to students from countries that are not well represented on its campus. The money helps pay tuition for 35 undergraduates who come primarily from South America and Southeast Asia. The financial awards are worth $7,500, with $5,000 in the form of a scholarship and the rest as work-study assistance.
To build bridges to new countries, especially to developing nations where families are less likely to be able to pay full tuition, financial aid is key, say international educators. While aid for foreign graduate students is common, assistance for undergraduates is not as widespread, they say.
Cincinnati's global scholarships, which were started in 2007, are worth $1,000 to $12,000. While more than half of the university's foreign-student population is from China and India, the financial awards have helped bring in more students from small countries like Nepal and Sri Lanka, says Mr. Cushing.
But financing is only one step in getting students to come. Officials say colleges must make sure they can accommodate students from new countries and different cultures.
"We're trying to figure out a way of making sure that once students land, they'll land happily and they'll stay," says Ross Jennings, vice president for international programs at Green River Community College. The college has been able to attract students from 45 countries to its campus, in Auburn, Wash., in part because it tries to make them feel comfortable far from home. For instance, it is trying to find land to build a soccer field, a seemingly small amenity but one that could convince Brazilian students to come north. "I don't want to stereotype them, but they do care about soccer," says Mr. Jennings.
In all, international-admissions offices often see a snowball effect when they start attracting more students from a new country or region: Successfully recruiting one or two students gets the ball rolling. If those students have a positive experience, they tell others back home, and applications increase.
Evelyn Levinson, director of international admissions at American University, says one way to get started is to connect with faculty members or former students in the specified country and build on those relationships.
The Washington, D.C., university has more than 140 nationalities represented on its campus, but three years ago it sought to be more deliberate about maintaining that diversity. Ms. Levinson emphasizes that traveling overseas to meet with overseas alumni, high-school counselors, and business people is key to fostering or rebuilding a student pipeline.
"It's all about trust, relationships, and eyeball contact," she says.
Yet as colleges try to get students from more countries on their campuses, they should also look for greater diversity among those who come from individual countries, like China, that send large numbers of students, says Seth Allen, vice president and dean of admissions and financial aid at Pomona College.
Some 30 percent of Pomona's international students are Chinese, but Mr. Allen is less concerned about that figure than about the backgrounds of such students. He recently took an 11-day tour of China with administrators from 11 other liberal-arts colleges to better understand the vast country and its huge population. He says the experience will help him find Chinese students outside the usual crop of applicants from the "feeder cities" of Beijing and Shanghai, giving Pomona a deeper application pool in terms of ethnicity and economic background.
When colleges mull their international diversity, they should think about those factors as well as geography, Mr. Allen says. "The world has such stratification between the socially privileged and the economically disadvantaged," he says.
If a college recruits the same kind of student, "whether it's students all from the same geographic location or it's students all from the same social station, there's a weakness there," he says. "It's not really preparing students to deal with the real complexity of the real world."
