illustrated in fig7 fig8 is an exploded perspective view of a preload adjustment unit illustrated in fig1 fig9 is a planer cross sectional view of the adjustable preload type linear guide system illustrated in fig1 fig1 is a cross sectional view of the preload adjustment unit illustrated in fig8 fig1 and 12 are enlarged views of portions of fig1 fig1 is an enlarged view of a portion of fig2 and the present invention will now be described more fully with reference to the accompanying drawings in which exemplary embodiments of the invention are shown fig1 is a perspective view of an adjustable preload type linear guide system according to an embodiment of the present invention and fig2 is an exploded perspective view of the adjustable preload type linear guide system illustrated in fig1 referring to fig1 and 2 the adjustable preload type linear guide system according to the current embodiment includes a base member 100 a slide member 200 and a preload adjustment unit 600 referring to fig3 and 4 the base member 100 includes a base body 101 and a pair of base rails 151 and 152 which are disposed on the base body 101 the base body 101 is formed of a light weight aluminum profile.