The value of lattice constants, physical broadening of X-ray reflections and the texture of a matrix and Al3Li superstructure in extrusions from 1420 alloy AL-Li-Mg the system in quenched and aged condition have been investigated by X-ray diffraction. It was established, that in both condition the atoms of magnesium and lithium occupy the site of crystal of lattice in matrix and super structure. It was determined that parameters alpha(Al) = 4.0694 angstrom and delta(1)(Al3Li) = 4.0728 angstrom, as alpha(Al)/delta(1)(Al3Li) misfit was 0.085%. The linear dependence of a cube of radius of a superstructure from aging indicates volumetric diffusion of their growth. It was shown, that in a direction of extrusion the matrix and superstructure phases have partial axial cubic (001) texture with a scattering angle of 20 degrees. In a matrix also it's watched the partial axial < 112 > component with a close scattering angle, which corresponds to of a plane deformation {110} < 112 > texture.