  In this paper, we obtain the parametric expressions of the canal
hypersurfaces that are formed as the envelope of a family of pseudo
hyperspheres or pseudo hyperbolic hyperspheres whose centers lie on a pseudo
null, partially null or null curves in $E^4_1$ and give their some geometric
invariants such as unit normal vector fields, Gaussian curvatures and mean
curvatures. Also, we construct some examples for these canal hypersurfaces and
finally, we give some characterizations for tubular hypersurfaces in $E^4_1$.
