A mask frame assembly in a cathode ray tube is capable of minimizing a howling phenomenon and preventing local wrinkles of a shadow mask by optimizing positioning of compression of the mask frame assembly. A mask frame assembly for applying optimal tension in a cathode ray tube includes a shadow mask for selecting color and a frame assembly having a main frame for applying tension to the shadow mask and a sub-frame for supporting the main frame, wherein each of compression points of the main frame is set to satisfy the following expressions, (L/2)×0.38≦X1≦(L/2)×0.52, and (L/2)×0.80≦X2×(L/2)×0.98, where L is a length of a long side of the main frame, X1 and X2 are distances from the center of the main frame to each of compression points P1 and P2 in both sides.