A high-density electrical connector comprises two sets of SMT contacts and two sets of DIP contacts, a dielectric housing formed by insert molding and a shield covering the housing, the dielectric housing comprises a pair of first housing members and a second housing member around the pair of first housing members, each first housing member is insert molded to a set of SMT contacts on one side thereof and a set of DIP contacts on an opposite side thereof in a first insert molding step, the second housing member is insert molded to and combines the pair of first housing members having the SMT contacts and the DIP contacts, thus, proper alignment, engagement, and coplanarity of the contacts assembled in the housing are easily obtained without interference from an insertion force.