A backplane connector assembly includes a first backplane connector and a second backplane connector. The first backplane connector includes a number of first conductive terminals, a first insulating bracket, a first metal shield, a second metal shield and a shielding space. The second backplane connector includes a second terminal module. Each second terminal module includes mating terminals mated with the first conductive terminals and a shielding shell surrounding a periphery of the mating terminals. The shielding shell is received in the shielding space. As a result, the backplane connector assembly of the present disclosure reduces crosstalk and improves the quality of signal transmission.