An electrical connector electrically connects a first electrical module and a second electrical module, for insertion by the first electrical module along a first direction. The electrical connector includes a first group of terminals arranged in a row along a second direction, having multiple signal terminals and multiple ground terminals and forming at least one first terminal unit and at least one second terminal unit. Each of the terminals has a contact portion, a tail portion, and a middle portion located between the contact portion and the tail portion. In the second direction, the middle portions of the first terminal unit form a first row of the middle portions, and the middle portions of the second terminal unit form a second row of the middle portions. Viewing from the second direction, the first and second rows of the middle portions are staggered, thus improving the crosstalk.