The men, all from London and aged between 24 and 43, are in custody and will appear before Westminster Magistrates' Court this week.
The charges include preparation and assisting others in preparation of acts of terrorism, support of a proscribed organisation, and conspiracy to possess false identity documents.
The six accused -- Michael Coe (33), Simon Keeler (43), Anthony Small (33), Zagum Perviaz (35), Hamzah Safdar (24) and Abdulraouf Eshati (28) -- were arrested at the Port of Dover in south-east England in November and in London earlier this month.
The arrests were made amid concerns that some British jihadists may have returned from Syria to plot attacks in the country.
More than 500 British Muslims are said to have travelled to Syria and Iraq to join jihadist groups.