The police said they have charged the men, all aged between 19 and 28, with plotting an explosion or explosions -- "of a nature likely to endanger life or cause serious injury to property" between October and December, in a run-up to Christmas.
The men have also been charged with involvement in the preparation of an attack by having downloaded and researched methods, materials and scouted potential targets.
One of the accused Gurukanth Desai, 28, is of Indian origin, and was arrested from Cardiff.
Two other were also arrested from Cardiff, two from East London and four from Stoke-on-Trent, the West Midlands police said.
The men arrested from Cardiff were identified as Omar Sharif Latif, 26; and Abdul Malik Miah, 24.
Those charged from London are Mohammed Moksudur Rahman Chowdhury, 20, and Shah Mohammed Lutfar Rahman, 28.
The four charged from Stoke-on-Trent are Nazam Hussain, 25; Usman Khan, 19; Mohibur Rahman, 26; and Abul Bosher Mohammed Shahjahan, 26.
In all, 12 men were arrested in raids co-ordinated by the West Midlands Counter Terrorism Unit on 20 December, but three were released without charge.
They will appear at the city of Westminster magistrates' court later.
The nine men are also accused under section 5(1) of the Terrorism Act 2006.
Sue Hemming, head of the Crown Prosecution Service Counter Terrorism Division, said: "I have advised the police that nine men should be charged with conspiracy to cause explosions and with engaging in conduct in preparation for acts of terrorism with the intention of either committing acts of terrorism, or assisting another to commit such acts."
She added: "Lawyers from the CPS Counter Terrorism Division have been working with the police on this case from an early stage and were on hand to give advice while the men were interviewed."
