Luo Ji
Luo Ji is the main character of the novel and is one of the four individuals selected by the UN to be part of the Wallfacer program.
Shi Qiang
Shi Qiang, also known as Da Shi, is the Wallfacer Head of Security 200 years after the beginning of the original Wallfacer program was started.
Zhuang Yen
Zhuang Yen is Luo Ji's wife who is kidnapped by the UN in a bid to get him to begin work on secret plans to combat the incoming Trisolarian invasion.
Frederick Tyler
A former US Defence Secretary and one of the four individuals selected as part of the Wallfacer program.
Rey Diaz
A former President of Venezuela and one of the four individuals selected as part of the Wallfacer program.
Bill Hines
An English neuroscientist and one of the four individuals selected as part of the Wallfacer program.
Ye Wenjie
The original astrophysicist in the first book of the trilogy who alerted the Trisolarians to the existence of the earth.