An electrical connector assembly comprises an electrical connector (2), a pick up cap (3) for engaging with the electrical connector (2). The electrical connector (2) comprises a housing (21), a plurality of terminals received in the housing (21). The housing (21) defines an opening (22) in a central position thereof and a pair of securing recesses (211) on two lateral sides of the housing (2) adjacent to the opening (22). The pick up cap (3) defines a smooth vacuum suction portion (32) in a central position thereof and a pair of rectangular holes (34) arranged on two sides of the vacuum suction portion (32), a pair of beams (35) disposed on sidewalls of the base portion adjacent to the holes (34). The beam (35) extends downwardly a pair of elastic hooks (31). The elastic hooks (31) engage with the securing recesses (211) of the base portion respectively.