A bollard fence that can be installed around a rack, the bollard fence comprising: two ground fixing members having a ground supporting portion of a lower portion thereof for fixing on the ground and an open groove formed at an upper portion thereof; two vertical poles of which lower ends are installed in the open grooves; L-connecting members having two perpendicular coupling portions and having a fastening slope between the two coupling portions; a horizontal frame coupled between the L-connecting members two-stage connectors having a vertical extension coupling groove formed at an upper end thereof and having a fastening portion at a lower end thereof, at which a fastening through-hole is formed, to be coupled in surface contact with the fastening slope; two sub-extension frames vertically coupled using the vertical extension coupling grooves; two L-couplers of which first ends are coupled to upper ends of the two sub-extension frames; and one sub-extension frame horizontally coupled between second ends of the L-couplers, wherein the vertical poles are coupled to the opening grooves of two ground fixing members, respectively, one ends of the L-connecting members are coupled to upper ends of the vertical poles, respectively, and the horizontal frame is installed between second ends of the L-connecting members, whereby a fence set (set A) is assembled and manufactured; and the two-stage connectors having the vertical extension coupling groove and the fastening portion are fastened respectively to the fastening slopes of the L-connecting members, the fastening portions of the two-stage connectors having the fastening through-hole are coupled in surface contact with the surface contact slopes of the L-connecting members using fasteners, the sub-extension frames are vertically installed in the vertical extension coupling grooves of the two-stage connectors, first ends of the L-couplers are coupled to upper ends of the vertically installed sub-extension frames, respectively, and one sub-extension frame is horizontally coupled to each of second ends of the L-coupling members, whereby the fence set (set A) is vertically extended. two ground fixing members having a ground supporting portion of a lower portion thereof for fixing on the ground and an open groove formed at an upper portion thereof; two vertical poles of which lower ends are installed in the open grooves; L-connecting members having two perpendicular coupling portions and having a fastening slope between the two coupling portions; a horizontal frame coupled between the L-connecting members two-stage connectors having a vertical extension coupling groove formed at an upper end thereof and having a fastening portion at a lower end thereof, at which a fastening through-hole is formed, to be coupled in surface contact with the fastening slope; two sub-extension frames vertically coupled using the vertical extension coupling grooves; two L-couplers of which first ends are coupled to upper ends of the two sub-extension frames; and one sub-extension frame horizontally coupled between second ends of the L-couplers, wherein the vertical poles are coupled to the opening grooves of two ground fixing members, respectively, one ends of the L-connecting members are coupled to upper ends of the vertical poles, respectively, and the horizontal frame is installed between second ends of the L-connecting members, whereby a fence set (set A) is assembled and manufactured; and the two-stage connectors having the vertical extension coupling groove and the fastening portion are fastened respectively to the fastening slopes of the L-connecting members, the fastening portions of the two-stage connectors having the fastening through-hole are coupled in surface contact with the surface contact slopes of the L-connecting members using fasteners, the sub-extension frames are vertically installed in the vertical extension coupling grooves of the two-stage connectors, first ends of the L-couplers are coupled to upper ends of the vertically installed sub-extension frames, respectively, and one sub-extension frame is horizontally coupled to each of second ends of the L-coupling members, whereby the fence set (set A) is vertically extended.