The anisotropy of cosmic microwave background radiation (CMBR) was measured by COBE satellite (Smoot et al. 1992). Their remarkable results show a rms-normalized amplitude of (1.3 ± 0.4) ×10−5 on the scale of 10° with a thermal spectrum for CMBR quadrupole anisotropy. In near future a new generation of COBE, e.g. COBERAS or Planck (Lubin, 1997) would be lunched, the precision of which is 3–4 magnitude higher than nowaday COBE's. But the anisotropy can be explained in a different way, since a 10−5 anisotropy on scale of 10° might be caused by voids and supercluster (Blumenthal et al., 1992). The additional redshift from voids or supercluster is called Rees-Sciama effects.