By SHARON LaFRANIERE

WUBU, China - For much of his education, Xue Longlong was silently accompanied from grade to grade, school to school, by a sealed Manila envelope stamped top secret. Stuffed inside were grades, test results, evaluations by fellow students and teachers, his Communist Party application and - most important for his job prospects - proof of his 2006 college degree.

Everyone in China who has been to high school has such a file. The files are irreplaceable histories of achievement and failure, the starting point for potential employers, government officials and others judging an individual’s worth. Often keys to the future, they are locked tight in government, school or workplace cabinets to eliminate any chance they might vanish.

But two years ago, Mr. Xue’s file did vanish. So did the files of at least 10 others, all 2006 college graduates with exemplary records, all from poor families living near this northcentral town on banks of the Yellow River.

With the Manila folders went their futures, they say.

Local officials said the files were lost when state workers moved them from the first to the second floor of a government building. But the graduates say they believe officials stole the files and sold them to underachievers seeking new identities and better job prospects.

Today, Mr. Xue, who had hoped to work at a state-owned oil company, sells real estate door to door, a step up from past jobs passing out leaflets and serving drinks at an Internet cafe. Wang Yong, who aspired to be a teacher or a bank officer, works odd jobs. Wang Jindong, who had a chance at a job at a state chemical firm, is a construction day laborer, earning less than $10 a day.

“If you don’t have it, just forget it!” Wang Jindong, now 27, said of his file. “No matter how capable you are, they will not hire you. Their first reaction is that you are a crook.”

Perhaps no group here is more vilified and mistrusted than China’s local officials, who shoulder much of the blame for corruption within the Communist Party. The party constantly vows to rein them in; in October, President Hu Jintao said a clean party was “a matter of life and death.”

But in Wubu, citizens say that local officials answer to no one, and that anyone who dares challenge them is punished.

Student files are a proven moneymaker for corrupt state workers. Four years ago, teachers in Jilin Province were caught selling two students’ files for $2,500 and $3,600; the police suspected that they intended to sell a dozen more. In May, the former head of a township government in Hunan Province admitted that he had paid more than $7,000 to steal the identity of a classmate of his daughter, so his daughter could attend college using the classmate’s records.

While not quite as important as in Communist China’s early days, when it was a powerful tool of social control, the file, called a dangan, is an absolute requirement for state employment and a means to bolster a candidate’s chances for some private- sector jobs, labor experts say. Because documents are collected over several years and signed by many people, they are virtually impossible to replicate.

Mr. Xue’s parents sacrificed even more than most, in the belief that education would lead their children out of poverty. They earn just $450 a year growing dates. His father, Xue Ruzhan, said he owed more than $10,000 - more than twice what his property is worth.

“What is the point of continuing to live?” the father said. “Sometimes I want to commit suicide. These corrupt officials destroyed all our hopes.”

Including, it seems, the hopes of Longlong’s younger sister, Xiaomei, an 11th grader who once thought she would follow him to a university degree.

No more. “I want to quit,” she said. “My brother graduated from college. What good did it do him?”