An electrical connector assembly as well as a board connector and a cable connector thereof are provided, in which power terminals and signal terminal are designed with different terminal structures in response to different functions, in order to ensure delivery of power and signal between the board connector and the cable connector, as well as reduce volumes occupied by the power terminals and the signal terminal in the board connector and the cable connector respectively, for achieving the purpose of reducing feature dimensions of the electrical connector assembly as well as the board connector and the cable connector thereof.