BEIJING - When several professors developed software to check for plagiarism in dissertations, they never expected that the software might later become a tool for smarter plagiarism.

An anti-plagiarism service, called Paper Misconduct Literature Check System (PMLC), has been made available on Taobao.com, China's largest online shopping website. After paying for the service, a student can have his paper checked, with the parts containing suspected plagiarism highlighted, thus allowing the student to change questionable parts and have his paper become qualified to receive a passing grade.

Ren Yan (not her real name), a postgraduate student from a university in Zhejiang, knew this trick well. One of her roommates, who was a law major, once used the software for an originality check of her graduation thesis, then rephrased the marked parts to assure that the paper passed.

A seller on Taobao, nicknamed "xxrsyh_2008," sold 1,564 anti-plagiarism services last month. He told Xinhua that the price of the service varies from 1 yuan (0.1518 U.S. dollar) to 200 yuan on Taobao.

From 2008 until now, 56 universities, including the renowned Tsinghua University, Renmin University of China and Shanghai Jiaotong University, have become users of the anti-plagiarism service.

Liu Xiaoping, a senior editor of the Journal of Northeastern University, said they had been using the software for originality checks since April 2009. Each month, they sent 30 to 50 articles to be checked. "Before the software was available, our editors had to do the anti-plagiarism checks on their own," she said. "The work was tiring and difficult."

Liu believed the software was very helpful.

"Plagiarism would damage the reputation of the journal," she said.

However, she saw some loopholes in the system.

"If a writer translated foreign articles, it might evade the check,"  she said.

One of the developers of the anti- plagiarism software is Shen Yang from the Information Engineering Department in Wuhan University in central China's Hubei Province, who developed the "Rost" software in 2007, which can be downloaded for free.

"The improvement in the technology cannot totally prevent plagiarism. It is just adding to the cost of plagiarism," he said.

Academic plagiarism is rampant in Chinese universities, involving both students and staff. Academic papers are offered for sale on the Internet and some people specialize in helping others to write academic papers.

In 2009 a teacher in Yunnan found that one of his papers had been plagiarized by a doctoral candidate from Beijing Normal University in collaboration with his tutor, a deputy president from Liaoning University.

Further, a survey by the East China Normal University on college students' online behavior showed that about 57 percent of respondents admitted they have copied research at least once.

A circular last year said that schools can postpone or refuse to grant degrees to cheats, or even revoke degrees already awarded. Also, tutors of students who commit fraud can be suspended or removed from their posts.

However, students believe the software alone cannot resolve the problem.

"I don't believe in such systems or software," said Chang Juan, a senior postgraduate from a university in Hubei, whose major is English, "The check might force some students to polish their writing skills, but not their creative thought."

Ren Yan shared her experience of avoiding plagiarism after using the checking software. "To sum up, paraphrase, abbreviate, be expansive. Not to copy without rewriting."

However, Shen Yang believed this amount of change is not enough.

"Without thinking about the origin of paper plagiarism and selling, the problems are still there," he said.

Additionally, Liu Xiaoping, the editor, suggested a reform in the evaluation method. "Many students and teachers were forced to plagiarize as the current grading system attached great importance to the quantity of the dissertations one published, rather than the quality," she said.