A spokesman for Durham University said developing its collections of art was "essential".
Students have called it a disgrace that the university spent £1.4m on art while increasing tuition fees to £9,000 a year.
But the statement, released by the university, said:
“Durham University is a custodian of many fine treasures and developing our collections of graphic art and sculpture for public display was an essential part of the original concept for the Palatine Centre.
“Some of the artwork was commissioned and reflects the University’s academic strengths and the heritage of our region.
“The works that can now be viewed represent a rich and varied presentation of 20th and 21st century art.
“The University organises free guided tours and staff, students and the public are encouraged to come and enjoy it.”
Durham University has spent £1.4m on art, including works by Pablo Picasso and Andy Warhol, while raising tuition fees for students. The costs have been uncovered by a Freedom of Information Act request by student journalists at Palatinate, the student newspaper.