Disclosed are a bottom spacer grid with a louver on a spring that can filter debris flowed through a channel of a lower end fitting with coolant on the lower end fitting of a nuclear fuel assembly, and can prevent uplift of fuel rods due to coolant, simultaneously.The bottom spacer grid for debris filtering with the louver for preventing uplift of the fuel rods, in the spacer grid equipped with a strip dividing a plurality of unit grid cells and a plurality of springs, protruded in uniform directions of each of vertical and horizontal directions on a grid surface of the strip, having uniform elasticity and supporting a lower end cap of a nuclear fuel rod, which includes: a spring having a plane portion with a predetermined size to contact to an outer circumference of the bottom end cap of the nuclear fuel rod; a louver protruded downward the spacer grid at a predetermined angle from the plane portion of the spring; and a debris filtering member bent and protruded to the bottom of the grid surface of the spacer grid.