Up for grabs will be 70 legislative council seats in the city of 7 million.
The 2014 Umbrella Movement was triggered by proposed changes to Hong Kong's electoral system that were seen to be a breach of the "One Country, Two Systems" policy, as China planned to screen all nominees in the first direct elections for Hong Kong's leader. The government eventually cleared protesters' tent city, without offering any concessions.
In the current election, Beijing's hand was again seen when Hong Kong's Electoral Affairs Commission ruled in July that all candidates must sign a pledge stating that the territory is an "inalienable" part of China.
The commission rejected applications from six candidates who were seen to be pro-independence.
Just two days before the polls open, China was still trying to pressure the Hong Kong government to disqualify another six candidates for the same reason, Reuters reported on Friday, citing sources with knowledge of the matter.