An electrical connector assembly includes an electrical connector and a protective cap assemble thereon. The electrical connector includes an insulative housing forming receiving cavity, and a plurality of contacts disposed in the housing and extending into the receiving cavity. The protective cap includes a planar body, a first latching section linked with the planar body, and an operation section extending above the planar body. A securing seat surrounds the housing and includes a second latching section engaged with the first latching section. By applying fingers upon the operation section to rotate/twist the cap, the first latching section and the second latching section is disengaged from each other, and the cap can be easily upwardly withdrawn from the securing seat.