Police fired rubber bullets and tear gas at between 200 and 300 protesters who gathered at the entrance of Middle East Technical University (METU), images broadcast on local television showed.
Police detained 14 people earlier in the afternoon during a demonstration against the city's plans, which include uprooting a large number of trees both inside and outside the campus.
University students began a sit-in protest to the plans for the campus -- one of the largest green spaces in the Turkish capital -- in the summer.
Armoured police took up positions around the park as calls for demonstrations were launched on social networks to protest the police repression in Ankara.
A peaceful sit-in to save Gezi Park and its 600 trees from being razed prompted a brutal police response on May 31, spiralling into nationwide protests against the government of Prime Minister Recep Tayyip Erdogan, seen as increasingly authoritarian.
Five people were killed and thousands injured during the unrest, which presented the Justice and Development Party (AKP) government with its biggest challenge since it came to power in 2002.