Abstract: The change of group interval will affect the migration of seismic data.Firstly,the length of group interval shall meet the spatial sampling law,provided otherwise,the aliasing will arise.Furthermore,the aliasing signals will affect the imaging quality in the process of migration.Secondly,the fi-nite difference migration algorithm of the approximate differ-ence operator or the conditional stability difference scheme shall be adopted in certain conditions,provided otherwise,the iterative computation will not be convergent with the dis-persion.However,for the difference migration and integra-tion migration of other formats,the less the group interval,the better the imaging quality.Except the above stability of numerical solution,the aliasing and the dispersion,the effect of high-density acquisition on migration appear in the in-creases in signal-to-noise ratio and visual resolution.