To provide a cover for a card connector and a card connector assembly using it for preventing without fail a child substrate from falling off the housing even if a shock of gravitational constant exceeding 10,000 m/s2 is applied on the surroundings of a card connector.

The cover 50 for a card connector 10 is provided with a flat plate part 51 almost entirely covering a top surface of the card connector 10 and a pressing part 52 equipped on the flat plate part 51. On the flat plate part 51 is formed a spring part 56 contacting a case C face of an electronic equipment containing the card connector 10. The pressing part 52 fixes a latch part 30 engaging with the child substrate furnished with the card connector 10. The card connector assembly 1 consists of the card connector 10 and the cover 50 for the card connector.