Molecular-beam epitaxy grown self-assembled InAs quantum dots (QDs) have been investigated by means of grazing incidence X-ray techniques. We reveal that the lateral distribution of InAs QDs is anisotropic and the most pronounced ordering of dot distribution is in [1 1 0] direction. Moreover, we determine the dot shape to be an octagonal-based truncated pyramid with {1 1 1} and {1 0 1} facet families. We also find that the strain is elastically relaxed with different components when dots are formed. The volume distribution of partially strained InAs inside QDs is peaked at intermediate strain values. In addition, a small volume fraction of relaxed InxGa1−xAs is found.