An electrical connector includes a hook-up pin mounted on one lateral side of the electrical connector. The hook-up pin includes a pin body, soldering sections respectively formed on two sides of an end of the pin body, an elastic pressing section formed on an end of the pin body that is adjacent to the soldering sections, and a hook section formed on an end of the elastic pressing section that is distant from the soldering sections. The soldering sections are arranged to clamp and be soldered to opposite sides of the circuit substrate. In inserting male and female parts of the present invention to each other, the soldering sections clamp on and are soldered to two sides of the circuit substrate so as to be resistant to the force of insertion and removal and be protected against damage. Further, the hook section helps prevent undesired detachment.