A fixing structure for an electronic card is suitable for mounting a long electronic card or a short electronic card within a housing. The fixing structure includes a pressing plate, a locking slice, and a locking member. Two ends of the pressing plate have two buckling portions. The locking slice connects an end of the pressing plate and has a locking hole. Besides, the locking slice leans against the housing. The locking member passes through the locking hole and is fixed into a first fixing hole or a second fixing hole. When the locking hole corresponds to the first fixing hole, the two buckling portions are fixed onto a free end of the long electronic card. When the locking hole is corresponding to the second fixing hole, the two buckling portions are fixed onto a free end of the short electronic card.