An electrical connector assembly (100), comprises an insulative housing (1) having a receiving space (14) therein communicated with an exterior along a longitudinal direction, a partition (15) formed in the receiving space and dividing the receiving space into a front receiving room (141) and a rear receiving room (142). Two PCB modules (2, 3) are arranged in a stacked manner and received into the receiving space. Each PCB module defines a mating section (210, 310) passing through the partition and received into the front receiving room. And two mating sections of the two PCB modules are spaced apart with each other along a vertical direction. And a latch (5) is assembled to the insulative housing.