A liftable slide cover mounting structure consisting of two hinges, two metal sheet bracket mechanism, two sliding rails, two gears, two gear racks and two supplementary support mechanisms. Subject to the use of the sheet plate bracket mechanisms to hold the sliding rails instead of zinc alloy sliding rail holders, the weight of the liftable slide cover mounting structure is minimized. Further, when the cover panel is opened from the base member, the sheet plate bracket mechanisms are forced into engagement with the supplementary support mechanisms to support the cover panel in position for enabling the user to operate the display screen of the cover panel positively.