A novel photographic silver halide emulsion is disclosed, which is useful in a color photographic silver halide material to provide improvements in image quality, storage stability and pressure resistance. The photographic silver halide emulsion comprises silver halide twinned crystal grains each having a ratio of grain diameter to grain thickness of 5 or less which amount to 50% or more by projection area of total grains, wherein X-ray diffraction pattern of the twinned crystal grains with Cu-K.alpha. ray as a radiation source has a (420) diffraction signal having a single peak; and the width of the peak at a height of 0.13 times the maximum peak height, based on the signal intensity, is 1.5 degree or less in a diffraction angle, 2.theta..