It is estimated that 10,000 students are attending the march, which began at 12pm today, following government cuts and the three-fold hike in tuition fees.
Protesters are also opposed to proposed plans to allow private providers to give degrees for the first time.
Students met at the University of London Union on Malet Street near Euston station and plan to march through Trafalgar Square, Fleet Street and finish at Moorgate in the City.
The Occupy London Camp will also join the demonstration and have put on a protest concert at St Paul’s with Billy Bragg, Chumbawamba and Rage Against the Machine playing from 3pm.
It is exactly one year after the students first protested against the government’s plans for higher education – a demonstration that ended in violence and chaos.
Police have prepared for unrest, with around 4,000 officers on duty, after an anarchist blog called on people to bring a “sea of rage” to London.
The police, supported by David Cameron, announced that there will be some officers carrying plastic bullets for “extreme” measures.
But Simon Pountain from Scotland Yard said: “These are carried by a small number of trained officers and are not held and used by those officers policing the route on Wednesday.”
Rumours that the police are planning to use a water cannon have been refuted by the Met.
From next year, universities will be able to charge fees of up to £9,000 per year.
