The University of Sydney has rejected allegations it unreasonably failed hundreds of international students studying post-graduate business programs.

About 37 per cent of the more than 1,200 students studying the Critical Thinking in Business (BUSS5000) course at the university's business school were given a fail grade after the first semester.

About 12 per cent of students in the Succeeding in Business (BUSS6000) course also failed.

Both courses are core units required to complete a Master of Commerce.

The University of Sydney's Business School Deputy Dean (Education), Professor John Shields, said the high number of fail grades came down to a change in the examination process.

"This semester, in both of these units we have introduced, for the first time, what's called a mandatory final exam," he said.

"A mandatory final exam means that a student cannot pass the unit unless they pass the exam."

Foreign students, many of them Chinese, made up the majority of students who failed.

Second-year student Jinyuan Li, who failed the BUSS6000 unit, said the course was too subjective.

"In the exam, all the questions were open-ended, but they had very limited marking criteria on their marking guide," he said.

Mr Li said the high failure rate was abnormal, particularly for the BUSS6000 course.

He said 42 students failed the course, which was a significant increase on previous semesters.

"For the BUSS5000 they say it's because their language skills are considered very poor," he said.

"But they cannot apply the same reason to ... BUSS6000 students because we are at our last semester.

"We never fail other courses, but we failed this one."

English language support services could become mandatory

Professor Shields acknowledged some Chinese students struggled with the course.

"We do have a large number of students coming to us from bachelor degrees undertaken elsewhere, including in mainland China, where the dominant mode of learning is what we would describe as passive learning rather than critical thinking and engaged learning," he said.

"What we've been seeking to do is transition students coming into our programs from that very different learning system or education values system to ... the critical thinking approach.

"I have to say, that's a work in progress."

Professor Shields said the university made services available to students who had difficulty with English.

"We have put in place quite systematic and comprehensive additional support for students that we identify as being at risk," he said.

"For example, in BUSS5000 we use a written communication diagnostic in the very first week of the students' enrolment in that unit.

"We identify students who we believe have a level of written communication proficiency that's substandard.

"We make available to them a zero credit, zero fee, intensive unit to help them sharpen their comprehension and communication skills."

He said the level of participation in those courses was "disappointing and we are moving towards making that support mandatory rather than voluntary".

Students consider formal appeals

Mr Li said many students sought informal appeals against their results, with most having the original fail grade upheld. Those students now plan to submit formal appeals.

"We will not give up," he said.

"We will not make mistakes."

Mr Li accused the university of missing deadlines in issuing responses to informal appeals, making it difficult for students starting the new semester.

"The new semester has begun for two weeks now and we don't know if we should enrol in this unit," he said.

"We are starting to lose faith in the university."

Mr Li said the issue had been given media coverage in China, and it could lead to a reduction in Chinese students choosing to study in Australia.

Professor Shields said the appeals could take time because they needed to be conducted "carefully and judiciously".

He said the university was focused on upholding academic integrity and ensuring procedural fairness for students, including those who passed the courses.

"Well over 400 [passed], most of them mainland Chinese students."