An electrical connector assembly (100) comprises an insulative body (1) integrally including a forward part (12) and a backward part (11). A main shell (32) includes a front pocket (320) enclosing the forward part (12), and a back segment (322) covering an upper portion of the backward part (11) of the body (1). A sub-shell (31) is assembled with the main shell (32), and includes a lower piece (316) covering a lower portion of the backward part (11). Therefore, the main shell (32), the sub-shell (31) are assembled with each other to provide a good shielding enclosure for the insulative body (1), where the contact terminals (2) are held therein.