Abstract: An electrode for electron guns of a color cathode ray tube includes an external rim electrode having a large electron beam-passing hole through which three electron beams pass; and first and second internal electrode pieces mounted in the large electron beam-passing hole, separated from each other and forming a central small electron beam-passing hole and two side small electron beam-passing holes wherein the central small electron beam-passing hole is defined by inner edges of the first and second internal electrode pieces, between the first and second internal electrode pieces, and the inner edges have the curvature of part of an ellipse having a major axis larger than the width of the large electron beam-passing hole.