The Electoral Affairs Commission said 58 per cent of the city's 3.8 million eligible voters had cast ballots, up from 53 per cent in 2012 and the highest turnout for any legislative election since 1997.
The turnout reflected the city's heightened political discontent and urgent appeals by candidates, some from new radical groups, jostling for extra votes in a highly competitive poll.
Much attention focused on a group of about 20 pro-democracy "localists" pushing a more radical, anti-China agenda who could become a fledgling new force in the legislature.
Despite the disqualification of six pro-democracy election candidates from the election in July on the grounds that they supported independence, preliminary results showed several localists and young democrats likely winning seats.
Full results are not expected till later today.
"The city's political spectrum has been stretched wider," said Wong Yuk Man, the head of Civic Passion, a radical pro-democracy group, who was vying for a seat. "It shows Hong Kong people are trying to get away from China, and from the Chinese Communist Party."
- Reuters, AAP