ASHINGTON, March 7 — Two out of three students must now borrow money to attend college, and four out of ten face unmanageable debts as they finish college and enter the job market, according to a report released today.

The report, by the lobbying arm of State Public Interest Research Groups, a nonprofit organization that studies social policy, found that debt among students doubled between 1992 and 2000, when the average graduate left college owing nearly $17,000 in educational loans. The figures are not adjusted for inflation, which remained low in that period.

Tracey King, an author of the report, said that higher education remained "a great investment," increasing a graduate's income over the course of a lifetime by more than $1 million.

"At the same time," Ms. King said, "students are having a hard time when they're graduating with all this debt and the payments are a high percentage of their income."

The report, based on data from the United States Census and the Department of Education's National Center for Education Statistics, found that the share of students borrowing to finance their education rose substantially, to 59 percent in 1996 from 42 percent in 1992. In that period, federal financing through Pell grants shrank as tuition rose.

Though Pell grants increased after 1996, the educational debt of graduating seniors jumped to $16,928 in 2000 from $9,188 in 1992. A third of students graduate owing more than $20,000 in education loans, and nearly half of all student borrowers graduate with credit card debts that average $3,176. By 2000, 64 percent of students relied on loans to help finance their education.

The report defines an unmanageable educational debt as one soaking up more than 8 percent of a person's monthly income. The report said this was a standard definition used by the loan industry.

Alyssa Ferree, a student at the University of California at Davis, said she had hoped to become a teacher or a social worker after graduating in 2004 with a degree in community and regional development. In California, New York and elsewhere in the country, school systems face a severe shortage of teachers, and the recruitment of fresh talent has been a priority of policy makers. But with her student loans set to reach $15,000 by graduation day, Ms. Ferree said she would have to aim for a better paying job after leaving college.

"When I entered college I knew I'd have debt," Ms. Ferree said, "but I didn't expect it to be this much."