An electric connector includes an insulation housing formed with a plurality of terminal slots, two positioning slots formed at two sides of the insulation housing, a plurality of terminals inserted into the terminal slots of the insulation housing, respectively, and two lateral fasteners arranged along and rotatable about a horizontal axis, each of which including a main body having a first end engaged with the corresponding positioning slot of the insulation housing. The first end of the main body is formed with an engagement structure. The insulation housing is formed with resilient members within the positioning slots. Each of the resilient members is formed with an engagement block. When the lateral fastener is inserted into the positioning slot, the engagement block engages with the engagement structure of the lateral fastener.