A blur compensation apparatus for X-ray image of an object to be examined used for a medical X-ray imaging apparatus, which has an X-ray generator and an X-ray imaging device opposite to the X-ray generator, said X-ray generator and said X-ray imaging device interposing therebetween said object held by an object holding means, wherein a sensor means for detecting blur movement of said object is provided near an objective projection position on said object holding means, and wherein a blur compensation process is executed for the X-ray image obtained by said X-ray imaging device, based on a positional change information which is calculated from a detection signal detected by said sensor means during X-ray radiography, said positional change information being the positional change amount with respect to said objective projection position relative to a reference position previously specified on said object holding means.